diff --git a/cmd/tools/fast/fast.v b/cmd/tools/fast/fast.v
index 99292c233c..3d061a54ea 100644
--- a/cmd/tools/fast/fast.v
+++ b/cmd/tools/fast/fast.v
@@ -50,7 +50,7 @@ fn main() {
 	date := time.unix(commit_date.int())
 	mut out := os.create('table.html') ?
 	// Place the new row on top
-	table = 
+	table =
 		'<tr>
 		<td>$date.format()</td>
 		<td><a target=_blank href="https://github.com/vlang/v/commit/$commit">$commit</a></td>
@@ -81,7 +81,7 @@ fn main() {
 }
 
 fn exec(s string) string {
-	e := os.exec(s) or { panic(err.msg) }
+	e := os.exec(s) or { panic(err) }
 	return e.output.trim_right('\r\n')
 }
 
@@ -111,7 +111,7 @@ fn measure(cmd string, description string) int {
 }
 
 fn measure_steps(vdir string) (int, int, int) {
-	resp := os.exec('$vdir/vprod -o v.c -show-timings $vdir/cmd/v') or { panic(err.msg) }
+	resp := os.exec('$vdir/vprod -o v.c -show-timings $vdir/cmd/v') or { panic(err) }
 	lines := resp.output.split_into_lines()
 	if lines.len != 3 {
 		return 0, 0, 0
diff --git a/cmd/tools/gen_vc.v b/cmd/tools/gen_vc.v
index 3f2033cee3..82cb8d855b 100644
--- a/cmd/tools/gen_vc.v
+++ b/cmd/tools/gen_vc.v
@@ -210,7 +210,7 @@ fn (mut gen_vc GenVC) generate() {
 	// check if gen_vc dir exists
 	if !os.is_dir(gen_vc.options.work_dir) {
 		// try create
-		os.mkdir(gen_vc.options.work_dir) or { panic(err.msg) }
+		os.mkdir(gen_vc.options.work_dir) or { panic(err) }
 		// still dosen't exist... we have a problem
 		if !os.is_dir(gen_vc.options.work_dir) {
 			gen_vc.logger.error('error creating directory: $gen_vc.options.work_dir')
@@ -246,8 +246,8 @@ fn (mut gen_vc GenVC) generate() {
 	ts_v := git_log_v.find_between('Date:', '\n').trim_space()
 	ts_vc := git_log_vc.find_between('Date:', '\n').trim_space()
 	// parse time as string to time.Time
-	last_commit_time_v := time.parse(ts_v) or { panic(err.msg) }
-	last_commit_time_vc := time.parse(ts_vc) or { panic(err.msg) }
+	last_commit_time_v := time.parse(ts_v) or { panic(err) }
+	last_commit_time_vc := time.parse(ts_vc) or { panic(err) }
 	// git dates are in users local timezone and v time.parse does not parse
 	// timezones at the moment, so for now get unix timestamp from output also
 	t_unix_v := git_log_v.find_between('Date Unix:', '\n').trim_space().int()
diff --git a/cmd/tools/missdoc.v b/cmd/tools/missdoc.v
index d5b40fbf0d..d6892eb90b 100644
--- a/cmd/tools/missdoc.v
+++ b/cmd/tools/missdoc.v
@@ -55,7 +55,7 @@ fn report_undocumented_functions_in_path(opt Options, path string) {
 }
 
 fn report_undocumented_functions_in_file(opt Options, file string) {
-	contents := os.read_file(file) or { panic(err.msg) }
+	contents := os.read_file(file) or { panic(err) }
 	lines := contents.split('\n')
 	mut info := []UndocumentedFN{}
 	for i, line in lines {
diff --git a/cmd/tools/modules/scripting/scripting.v b/cmd/tools/modules/scripting/scripting.v
index ce06294979..19d7c0ae36 100644
--- a/cmd/tools/modules/scripting/scripting.v
+++ b/cmd/tools/modules/scripting/scripting.v
@@ -53,9 +53,9 @@ pub fn rmrf(path string) {
 	verbose_trace(@FN, 'rm -rf $path')
 	if os.exists(path) {
 		if os.is_dir(path) {
-			os.rmdir_all(path) or { panic(err.msg) }
+			os.rmdir_all(path) or { panic(err) }
 		} else {
-			os.rm(path) or { panic(err.msg) }
+			os.rm(path) or { panic(err) }
 		}
 	}
 }
diff --git a/cmd/tools/modules/testing/common.v b/cmd/tools/modules/testing/common.v
index 673ea63aec..3cf4e846bf 100644
--- a/cmd/tools/modules/testing/common.v
+++ b/cmd/tools/modules/testing/common.v
@@ -221,7 +221,7 @@ pub fn (mut ts TestSession) test() {
 	// cleanup generated .tmp.c files after successfull tests:
 	if ts.benchmark.nfail == 0 {
 		if ts.rm_binaries {
-			os.rmdir_all(ts.vtmp_dir) or { panic(err.msg) }
+			os.rmdir_all(ts.vtmp_dir) or { panic(err) }
 		}
 	}
 }
@@ -255,7 +255,7 @@ fn worker_trunner(mut p pool.PoolProcessor, idx int, thread_id int) voidptr {
 	generated_binary_fpath := os.join_path(tmpd, generated_binary_fname)
 	if os.exists(generated_binary_fpath) {
 		if ts.rm_binaries {
-			os.rm(generated_binary_fpath) or { panic(err.msg) }
+			os.rm(generated_binary_fpath) or { panic(err) }
 		}
 	}
 	mut cmd_options := [ts.vargs]
@@ -308,7 +308,7 @@ fn worker_trunner(mut p pool.PoolProcessor, idx int, thread_id int) voidptr {
 	}
 	if os.exists(generated_binary_fpath) {
 		if ts.rm_binaries {
-			os.rm(generated_binary_fpath) or { panic(err.msg) }
+			os.rm(generated_binary_fpath) or { panic(err) }
 		}
 	}
 	return pool.no_result
@@ -358,7 +358,7 @@ pub fn prepare_test_session(zargs string, folder string, oskipped []string, main
 				continue
 			}
 		}
-		c := os.read_file(f) or { panic(err.msg) }
+		c := os.read_file(f) or { panic(err) }
 		maxc := if c.len > 300 { 300 } else { c.len }
 		start := c[0..maxc]
 		if start.contains('module ') && !start.contains('module main') {
@@ -436,7 +436,7 @@ pub fn header(msg string) {
 pub fn setup_new_vtmp_folder() string {
 	now := time.sys_mono_now()
 	new_vtmp_dir := os.join_path(os.temp_dir(), 'v', 'test_session_$now')
-	os.mkdir_all(new_vtmp_dir) or { panic(err.msg) }
+	os.mkdir_all(new_vtmp_dir) or { panic(err) }
 	os.setenv('VTMP', new_vtmp_dir, true)
 	return new_vtmp_dir
 }
diff --git a/cmd/tools/oldv.v b/cmd/tools/oldv.v
index c295f91079..afdbb8f121 100644
--- a/cmd/tools/oldv.v
+++ b/cmd/tools/oldv.v
@@ -101,7 +101,7 @@ fn main() {
 	scripting.cprintln('#   checkout folder: $context.path_v')
 	if context.cmd_to_run.len > 0 {
 		cmdres := os.exec(context.cmd_to_run) or {
-			panic(err.msg)
+			panic(err)
 		}
 		scripting.cprintln('#           command: ${context.cmd_to_run:-34s} exit code: ${cmdres.exit_code:-4d}  result:')
 		println(cmdres.output)
diff --git a/cmd/tools/test_if_v_test_system_works.v b/cmd/tools/test_if_v_test_system_works.v
index e57d5814f1..11596cee27 100644
--- a/cmd/tools/test_if_v_test_system_works.v
+++ b/cmd/tools/test_if_v_test_system_works.v
@@ -28,16 +28,16 @@ fn get_vexe_path() string {
 fn new_tdir() string {
 	tdir_ := os.join_path(os.temp_dir(), rand.ulid())
 	if os.exists(tdir_) {
-		os.rmdir(tdir_) or { panic(err.msg) }
+		os.rmdir(tdir_) or { panic(err) }
 	}
-	os.mkdir(tdir_) or { panic(err.msg) }
+	os.mkdir(tdir_) or { panic(err) }
 	C.atexit(cleanup_tdir)
 	return tdir_
 }
 
 fn cleanup_tdir() {
 	println('... removing tdir: $tdir')
-	os.rmdir_all(tdir) or { panic(err.msg) }
+	os.rmdir_all(tdir) or { panic(err) }
 }
 
 fn main() {
@@ -55,7 +55,7 @@ fn main() {
 
 fn check_ok(cmd string) string {
 	println('>   check_ok cmd: $cmd')
-	res := os.exec(cmd) or { panic(err.msg) }
+	res := os.exec(cmd) or { panic(err) }
 	if res.exit_code != 0 {
 		eprintln('>   check_ok failed.\n$res.output')
 		exit(1)
@@ -65,7 +65,7 @@ fn check_ok(cmd string) string {
 
 fn check_fail(cmd string) string {
 	println('> check_fail cmd: $cmd')
-	res := os.exec(cmd) or { panic(err.msg) }
+	res := os.exec(cmd) or { panic(err) }
 	if res.exit_code == 0 {
 		eprintln('> check_fail succeeded, but it should have failed.\n$res.output')
 		exit(1)
diff --git a/cmd/tools/vbuild-tools.v b/cmd/tools/vbuild-tools.v
index 3ad76af562..c72dcab3a9 100644
--- a/cmd/tools/vbuild-tools.v
+++ b/cmd/tools/vbuild-tools.v
@@ -55,7 +55,7 @@ fn main() {
 		//
 		tpath := os.join_path(session.vtmp_dir, texe)
 		if tname in tools_in_subfolders {
-			os.mv_by_cp(tpath, os.join_path(tfolder, tname, texe)) or { panic(err.msg) }
+			os.mv_by_cp(tpath, os.join_path(tfolder, tname, texe)) or { panic(err) }
 			continue
 		}
 		os.mv_by_cp(tpath, os.join_path(tfolder, texe)) or {
diff --git a/cmd/tools/vcheck-md.v b/cmd/tools/vcheck-md.v
index b8ad64d650..5fcba74c2c 100644
--- a/cmd/tools/vcheck-md.v
+++ b/cmd/tools/vcheck-md.v
@@ -244,7 +244,7 @@ fn (mut f MDFile) check_examples() (int, int) {
 		mut should_cleanup_vfile := true
 		// eprintln('>>> checking example $vfile ...')
 		vcontent := e.text.join('\n') + '\n'
-		os.write_file(vfile, vcontent) or { panic(err.msg) }
+		os.write_file(vfile, vcontent) or { panic(err) }
 		mut acommands := e.command.split(' ')
 		nofmt := 'nofmt' in acommands
 		for command in acommands {
@@ -331,7 +331,7 @@ fn (mut f MDFile) check_examples() (int, int) {
 			}
 		}
 		if should_cleanup_vfile {
-			os.rm(vfile) or { panic(err.msg) }
+			os.rm(vfile) or { panic(err) }
 		}
 	}
 	return errors, oks
diff --git a/cmd/tools/vcreate.v b/cmd/tools/vcreate.v
index 39cc227360..84d8229124 100644
--- a/cmd/tools/vcreate.v
+++ b/cmd/tools/vcreate.v
@@ -58,7 +58,7 @@ fn (c &Create) write_vmod(new bool) {
 		cerror(err.msg)
 		exit(1)
 	}
-	vmod.write_str(vmod_content(c.name, c.description)) or { panic(err.msg) }
+	vmod.write_str(vmod_content(c.name, c.description)) or { panic(err) }
 	vmod.close()
 }
 
@@ -71,7 +71,7 @@ fn (c &Create) write_main(new bool) {
 		cerror(err.msg)
 		exit(2)
 	}
-	mainfile.write_str(main_content()) or { panic(err.msg) }
+	mainfile.write_str(main_content()) or { panic(err) }
 	mainfile.close()
 }
 
@@ -87,7 +87,7 @@ fn (c &Create) create_git_repo(dir string) {
 				// We don't really need a .gitignore, it's just a nice-to-have
 				return
 			}
-			fl.write_str(gen_gitignore(c.name)) or { panic(err.msg) }
+			fl.write_str(gen_gitignore(c.name)) or { panic(err) }
 			fl.close()
 		}
 	}
@@ -110,7 +110,7 @@ fn create() {
 	}
 	c.description = os.input('Input your project description: ')
 	println('Initialising ...')
-	os.mkdir(c.name) or { panic(err.msg) }
+	os.mkdir(c.name) or { panic(err) }
 	c.write_vmod(true)
 	c.write_main(true)
 	c.create_git_repo(c.name)
diff --git a/cmd/tools/vdoc/html.v b/cmd/tools/vdoc/html.v
index aa554d2a8b..0da4da7509 100644
--- a/cmd/tools/vdoc/html.v
+++ b/cmd/tools/vdoc/html.v
@@ -126,7 +126,7 @@ fn (vd VDoc) render_search_index(out Output) {
 	js_search_index.writeln('];')
 	js_search_data.writeln('];')
 	out_file_path := os.join_path(out.path, 'search_index.js')
-	os.write_file(out_file_path, js_search_index.str() + js_search_data.str()) or { panic(err.msg) }
+	os.write_file(out_file_path, js_search_index.str() + js_search_data.str()) or { panic(err) }
 }
 
 fn (mut vd VDoc) render_static_html(out Output) {
@@ -162,7 +162,7 @@ fn (vd VDoc) get_resource(name string, out Output) string {
 		output_path := os.join_path(out.path, name)
 		if !os.exists(output_path) {
 			println('Generating $out.typ in "$output_path"')
-			os.write_file(output_path, res) or { panic(err.msg) }
+			os.write_file(output_path, res) or { panic(err) }
 		}
 		return name
 	}
diff --git a/cmd/tools/vdoc/vdoc.v b/cmd/tools/vdoc/vdoc.v
index edf1d3a8aa..fce9a448c9 100644
--- a/cmd/tools/vdoc/vdoc.v
+++ b/cmd/tools/vdoc/vdoc.v
@@ -162,7 +162,7 @@ fn (vd VDoc) work_processor(mut work sync.Channel, mut wg sync.WaitGroup) {
 		file_name, content := vd.render_doc(pdoc.d, pdoc.out)
 		output_path := os.join_path(pdoc.out.path, file_name)
 		println('Generating $pdoc.out.typ in "$output_path"')
-		os.write_file(output_path, content) or { panic(err.msg) }
+		os.write_file(output_path, content) or { panic(err) }
 	}
 	wg.done()
 }
@@ -350,15 +350,15 @@ fn (mut vd VDoc) generate_docs_from_file() {
 			out.path = os.real_path('.')
 		}
 		if !os.exists(out.path) {
-			os.mkdir(out.path) or { panic(err.msg) }
+			os.mkdir(out.path) or { panic(err) }
 		}
 		if cfg.is_multi {
 			out.path = os.join_path(out.path, '_docs')
 			if !os.exists(out.path) {
-				os.mkdir(out.path) or { panic(err.msg) }
+				os.mkdir(out.path) or { panic(err) }
 			} else {
 				for fname in css_js_assets {
-					os.rm(os.join_path(out.path, fname)) or { panic(err.msg) }
+					os.rm(os.join_path(out.path, fname)) or { panic(err) }
 				}
 			}
 		}
@@ -372,11 +372,11 @@ fn (mut vd VDoc) generate_docs_from_file() {
 			vd.render_search_index(out)
 			// move favicons to target directory
 			println('Copying favicons...')
-			favicons := os.ls(favicons_path) or { panic(err.msg) }
+			favicons := os.ls(favicons_path) or { panic(err) }
 			for favicon in favicons {
 				favicon_path := os.join_path(favicons_path, favicon)
 				destination_path := os.join_path(out.path, favicon)
-				os.cp(favicon_path, destination_path) or { panic(err.msg) }
+				os.cp(favicon_path, destination_path) or { panic(err) }
 			}
 		}
 	}
diff --git a/cmd/tools/vfmt.v b/cmd/tools/vfmt.v
index 6fa0ef7118..01b06c5047 100644
--- a/cmd/tools/vfmt.v
+++ b/cmd/tools/vfmt.v
@@ -175,7 +175,7 @@ fn (foptions &FormatOptions) format_file(file string) {
 	file_name := os.file_name(file)
 	ulid := rand.ulid()
 	vfmt_output_path := os.join_path(vtmp_folder, 'vfmt_${ulid}_$file_name')
-	os.write_file(vfmt_output_path, formatted_content) or { panic(err.msg) }
+	os.write_file(vfmt_output_path, formatted_content) or { panic(err) }
 	if foptions.is_verbose {
 		eprintln('fmt.fmt worked and $formatted_content.len bytes were written to $vfmt_output_path .')
 	}
@@ -266,7 +266,7 @@ fn (foptions &FormatOptions) post_process_file(file string, formatted_file_path
 	}
 	if foptions.is_w {
 		if is_formatted_different {
-			os.mv_by_cp(formatted_file_path, file) or { panic(err.msg) }
+			os.mv_by_cp(formatted_file_path, file) or { panic(err) }
 			eprintln('Reformatted file: $file')
 		} else {
 			eprintln('Already formatted file: $file')
@@ -277,7 +277,7 @@ fn (foptions &FormatOptions) post_process_file(file string, formatted_file_path
 }
 
 fn (f FormatOptions) str() string {
-	return 
+	return
 		'FormatOptions{ is_l: $f.is_l, is_w: $f.is_w, is_diff: $f.is_diff, is_verbose: $f.is_verbose,' +
 		' is_all: $f.is_all, is_worker: $f.is_worker, is_debug: $f.is_debug, is_noerror: $f.is_noerror,' +
 		' is_verify: $f.is_verify" }'
@@ -312,7 +312,7 @@ fn get_compile_name_of_potential_v_project(file string) string {
 	pfolder := os.real_path(os.dir(file))
 	// a .v project has many 'module main' files in one folder
 	// if there is only one .v file, then it must be a standalone
-	all_files_in_pfolder := os.ls(pfolder) or { panic(err.msg) }
+	all_files_in_pfolder := os.ls(pfolder) or { panic(err) }
 	mut vfiles := []string{}
 	for f in all_files_in_pfolder {
 		vf := os.join_path(pfolder, f)
@@ -332,7 +332,7 @@ fn get_compile_name_of_potential_v_project(file string) string {
 	// a project folder, that should be compiled with `v pfolder`.
 	mut main_fns := 0
 	for f in vfiles {
-		slines := read_source_lines(f) or { panic(err.msg) }
+		slines := read_source_lines(f) or { panic(err) }
 		for line in slines {
 			if line.contains('fn main()') {
 				main_fns++
diff --git a/cmd/tools/vpm.v b/cmd/tools/vpm.v
index 864f4a069b..f196e52d5d 100644
--- a/cmd/tools/vpm.v
+++ b/cmd/tools/vpm.v
@@ -71,7 +71,7 @@ fn main() {
 		'install' {
 			if module_names.len == 0 && os.exists('./v.mod') {
 				println('Detected v.mod file inside the project directory. Using it...')
-				manifest := vmod.from_file('./v.mod') or { panic(err.msg) }
+				manifest := vmod.from_file('./v.mod') or { panic(err) }
 				module_names = manifest.dependencies
 			}
 			vpm_install(module_names)
@@ -331,13 +331,13 @@ fn vpm_remove(module_names []string) {
 		final_module_path := valid_final_path_of_existing_module(name) or { continue }
 		println('Removing module "$name"...')
 		verbose_println('removing folder $final_module_path')
-		os.rmdir_all(final_module_path) or { panic(err.msg) }
+		os.rmdir_all(final_module_path) or { panic(err) }
 		// delete author directory if it is empty
 		author := name.split('.')[0]
 		author_dir := os.real_path(os.join_path(settings.vmodules_path, author))
 		if os.is_dir_empty(author_dir) {
 			verbose_println('removing author folder $author_dir')
-			os.rmdir(author_dir) or { panic(err.msg) }
+			os.rmdir(author_dir) or { panic(err) }
 		}
 	}
 }
@@ -364,7 +364,7 @@ fn valid_final_path_of_existing_module(name string) ?string {
 fn ensure_vmodules_dir_exist() {
 	if !os.is_dir(settings.vmodules_path) {
 		println('Creating $settings.vmodules_path/ ...')
-		os.mkdir(settings.vmodules_path) or { panic(err.msg) }
+		os.mkdir(settings.vmodules_path) or { panic(err) }
 	}
 }
 
@@ -411,7 +411,7 @@ fn get_installed_modules() []string {
 
 fn get_all_modules() []string {
 	url := get_working_server_url()
-	r := http.get(url) or { panic(err.msg) }
+	r := http.get(url) or { panic(err) }
 	if r.status_code != 200 {
 		println('Failed to search vpm.vlang.io. Status code: $r.status_code')
 		exit(1)
diff --git a/cmd/tools/vrepl.v b/cmd/tools/vrepl.v
index 9f38d0a72b..2425651e7d 100644
--- a/cmd/tools/vrepl.v
+++ b/cmd/tools/vrepl.v
@@ -184,7 +184,7 @@ fn run_repl(workdir string, vrepl_prefix string) {
 		}
 		if r.line.starts_with('print') {
 			source_code := r.current_source_code(false) + '\n$r.line\n'
-			os.write_file(file, source_code) or { panic(err.msg) }
+			os.write_file(file, source_code) or { panic(err) }
 			s := repl_run_vfile(file) or { return }
 			print_output(s)
 		} else {
@@ -251,7 +251,7 @@ fn run_repl(workdir string, vrepl_prefix string) {
 				}
 				temp_source_code = r.current_source_code(true) + '\n$temp_line\n'
 			}
-			os.write_file(temp_file, temp_source_code) or { panic(err.msg) }
+			os.write_file(temp_file, temp_source_code) or { panic(err) }
 			s := repl_run_vfile(temp_file) or { return }
 			if !func_call && s.exit_code == 0 && !temp_flag {
 				for r.temp_lines.len > 0 {
diff --git a/cmd/tools/vself.v b/cmd/tools/vself.v
index 0ba5c9fa8e..9bf7269332 100644
--- a/cmd/tools/vself.v
+++ b/cmd/tools/vself.v
@@ -27,12 +27,12 @@ fn main() {
 		// The user just wants an independent copy of v, and so we are done.
 		return
 	}
-	backup_old_version_and_rename_newer() or { panic(err.msg) }
+	backup_old_version_and_rename_newer() or { panic(err) }
 	println('V built successfully!')
 }
 
 fn compile(vroot string, cmd string) {
-	result := os.exec(cmd) or { panic(err.msg) }
+	result := os.exec(cmd) or { panic(err) }
 	if result.exit_code != 0 {
 		eprintln('cannot compile to `$vroot`: \n$result.output')
 		exit(1)
@@ -76,7 +76,7 @@ fn backup_old_version_and_rename_newer() ?bool {
 	os.rm(v_file) or { }
 
 	list_folder('', 'moving $v2_file to $v_file ...')
-	os.mv_by_cp(v2_file, v_file) or { panic(err.msg) }
+	os.mv_by_cp(v2_file, v_file) or { panic(err) }
 
 	list_folder('after:', '')
 
diff --git a/cmd/tools/vsetup-freetype.v b/cmd/tools/vsetup-freetype.v
index b640f12167..0d4b33f14e 100644
--- a/cmd/tools/vsetup-freetype.v
+++ b/cmd/tools/vsetup-freetype.v
@@ -12,7 +12,7 @@ fn main() {
 			println('Thirdparty "freetype" is already installed.')
 		} else {
 			s := os.exec('git clone --depth=1 https://github.com/ubawurinna/freetype-windows-binaries ./thirdparty/freetype/') or {
-				panic(err.msg)
+				panic(err)
 			}
 			println(s.output)
 			println('Thirdparty "freetype" installed successfully.')
diff --git a/cmd/tools/vsymlink.v b/cmd/tools/vsymlink.v
index a0f99587bb..881da93d57 100644
--- a/cmd/tools/vsymlink.v
+++ b/cmd/tools/vsymlink.v
@@ -27,11 +27,11 @@ fn setup_symlink_unix(vexe string) {
 	if os.system("uname -o | grep -q '[A/a]ndroid'") == 1 {
 		link_dir := '/usr/local/bin'
 		if !os.exists(link_dir) {
-			os.mkdir_all(link_dir) or { panic(err.msg) }
+			os.mkdir_all(link_dir) or { panic(err) }
 		}
 		link_path = link_dir + '/v'
 	}
-	ret := os.exec('ln -sf $vexe $link_path') or { panic(err.msg) }
+	ret := os.exec('ln -sf $vexe $link_path') or { panic(err) }
 	if ret.exit_code == 0 {
 		println('Symlink "$link_path" has been created')
 	} else {
@@ -49,14 +49,14 @@ fn setup_symlink_windows(vexe string) {
 		mut vsymlink := os.join_path(vsymlinkdir, 'v.exe')
 		// Remove old symlink first (v could have been moved, symlink rerun)
 		if !os.exists(vsymlinkdir) {
-			os.mkdir(vsymlinkdir) or { panic(err.msg) }
+			os.mkdir(vsymlinkdir) or { panic(err) }
 		} else {
 			if os.exists(vsymlink) {
-				os.rm(vsymlink) or { panic(err.msg) }
+				os.rm(vsymlink) or { panic(err) }
 			} else {
 				vsymlink = os.join_path(vsymlinkdir, 'v.bat')
 				if os.exists(vsymlink) {
-					os.rm(vsymlink) or { panic(err.msg) }
+					os.rm(vsymlink) or { panic(err) }
 				}
 				vsymlink = os.join_path(vsymlinkdir, 'v.exe')
 			}
@@ -69,9 +69,9 @@ fn setup_symlink_windows(vexe string) {
 			eprintln('Creating a batch file instead...')
 			vsymlink = os.join_path(vsymlinkdir, 'v.bat')
 			if os.exists(vsymlink) {
-				os.rm(vsymlink) or { panic(err.msg) }
+				os.rm(vsymlink) or { panic(err) }
 			}
-			os.write_file(vsymlink, '@echo off\n$vexe %*') or { panic(err.msg) }
+			os.write_file(vsymlink, '@echo off\n$vexe %*') or { panic(err) }
 			eprintln('$vsymlink file written.')
 		}
 		if !os.exists(vsymlink) {
diff --git a/cmd/tools/vup.v b/cmd/tools/vup.v
index bd45d6e77e..7ff83b8f69 100644
--- a/cmd/tools/vup.v
+++ b/cmd/tools/vup.v
@@ -41,7 +41,7 @@ fn main() {
 		app.backup('cmd/tools/vup.exe')
 	}
 	app.recompile_v()
-	os.exec('"$app.vexe" cmd/tools/vup.v') or { panic(err.msg) }
+	os.exec('"$app.vexe" cmd/tools/vup.v') or { panic(err) }
 	app.show_current_v_version()
 }
 
@@ -88,7 +88,7 @@ fn (app App) make(vself string) {
 	$if windows {
 		make = 'make.bat'
 	}
-	make_result := os.exec(make) or { panic(err.msg) }
+	make_result := os.exec(make) or { panic(err) }
 	app.vprintln(make_result.output)
 }
 
@@ -121,7 +121,7 @@ fn (app App) git_command(command string) {
 	git_result := os.exec('git $command') or {
 		app.get_git()
 		// Try it again with (maybe) git installed
-		os.exec('git $command') or { panic(err.msg) }
+		os.exec('git $command') or { panic(err) }
 	}
 	if git_result.exit_code != 0 {
 		eprintln(git_result.output)
@@ -136,11 +136,11 @@ fn (app App) get_git() {
 		// We'll use 32 bit because maybe someone out there is using 32-bit windows
 		os.exec('bitsadmin.exe /transfer "vgit" https://github.com/git-for-windows/git/releases/download/v2.30.0.windows.2/Git-2.30.0.2-32-bit.exe "$os.getwd()/git32.exe"') or {
 			eprintln('Unable to install git automatically: please install git manually')
-			panic(err.msg)
+			panic(err)
 		}
 		os.exec('$os.getwd()/git32.exe') or {
 			eprintln('Unable to install git automatically: please install git manually')
-			panic(err.msg)
+			panic(err)
 		}
 	} $else { // Probably some kind of *nix, usually need to get using a package manager.
 		eprintln("error: Install `git` using your system's package manager")
diff --git a/cmd/tools/vvet/vet_test.v b/cmd/tools/vvet/vet_test.v
index fa7fa538d4..6209f9168c 100644
--- a/cmd/tools/vvet/vet_test.v
+++ b/cmd/tools/vvet/vet_test.v
@@ -21,7 +21,7 @@ fn test_vet() {
 }
 
 fn get_tests_in_dir(dir string) []string {
-	files := os.ls(dir) or { panic(err.msg) }
+	files := os.ls(dir) or { panic(err) }
 	mut tests := files.filter(it.ends_with('.vv'))
 	tests.sort()
 	return tests
@@ -34,8 +34,8 @@ fn check_path(vexe string, dir string, tests []string) int {
 		program := path
 		print(path + ' ')
 		// -force is needed so that `v vet` would not skip the regression files
-		res := os.exec('$vexe vet -force $program') or { panic(err.msg) }
-		mut expected := os.read_file(program.replace('.vv', '') + '.out') or { panic(err.msg) }
+		res := os.exec('$vexe vet -force $program') or { panic(err) }
+		mut expected := os.read_file(program.replace('.vv', '') + '.out') or { panic(err) }
 		expected = clean_line_endings(expected)
 		found := clean_line_endings(res.output)
 		if expected != found {
diff --git a/examples/database/orm.v b/examples/database/orm.v
index 4e3303060e..2a39a82dfb 100644
--- a/examples/database/orm.v
+++ b/examples/database/orm.v
@@ -16,7 +16,7 @@ struct User {
 }
 
 fn main() {
-	db := sqlite.connect(':memory:') or { panic(err.msg) }
+	db := sqlite.connect(':memory:') or { panic(err) }
 	db.exec('drop table if exists User')
 	db.exec("create table Module (id integer primary key, name text default '', nr_downloads int default 0, creator int default 0);")
 	db.exec("create table User (id integer primary key, age int default 0, name text default '', is_customer int default 0);")
@@ -33,12 +33,12 @@ fn main() {
 	sql db {
 		insert mod into Module
 	}
-	
+
 	modul := sql db {
 		select from Module where id == 1
 	}
 
 	println(modul.name)
 	println(modul.creator.name)
-	
+
 }
diff --git a/examples/database/pg/customer.v b/examples/database/pg/customer.v
index 2dac25ddb9..d159b83c6b 100644
--- a/examples/database/pg/customer.v
+++ b/examples/database/pg/customer.v
@@ -41,7 +41,7 @@ fn main() {
 
 	// by adding `limit 1` we tell V that there will be only one object
 	println(dash)
-	existing := db.select from Customer where id == 1 limit 1 or { panic(err.msg) }
+	existing := db.select from Customer where id == 1 limit 1 or { panic(err) }
 	println('Existing customer name: $existing.name')
 	println('Existing customer full information:')
 	println(existing)
diff --git a/examples/flappylearning/game.v b/examples/flappylearning/game.v
index 7c045607c9..5b1ef094dc 100644
--- a/examples/flappylearning/game.v
+++ b/examples/flappylearning/game.v
@@ -212,13 +212,13 @@ fn (mut app App) run() {
 
 fn init_images(mut app App) {
 	$if android {
-		background := os.read_apk_asset('img/background.png') or { panic(err.msg) }
+		background := os.read_apk_asset('img/background.png') or { panic(err) }
 		app.background = app.gg.create_image_from_byte_array(background)
-		bird := os.read_apk_asset('img/bird.png') or { panic(err.msg) }
+		bird := os.read_apk_asset('img/bird.png') or { panic(err) }
 		app.bird = app.gg.create_image_from_byte_array(bird)
-		pipetop := os.read_apk_asset('img/pipetop.png') or { panic(err.msg) }
+		pipetop := os.read_apk_asset('img/pipetop.png') or { panic(err) }
 		app.pipetop = app.gg.create_image_from_byte_array(pipetop)
-		pipebottom := os.read_apk_asset('img/pipebottom.png') or { panic(err.msg) }
+		pipebottom := os.read_apk_asset('img/pipebottom.png') or { panic(err) }
 		app.pipebottom = app.gg.create_image_from_byte_array(pipebottom)
 	} $else {
 		app.background = app.gg.create_image(os.resource_abs_path('assets/img/background.png'))
diff --git a/examples/path_tracing.v b/examples/path_tracing.v
index dbc6ea66dc..2c32ae96bc 100644
--- a/examples/path_tracing.v
+++ b/examples/path_tracing.v
@@ -98,15 +98,15 @@ fn new_image(w int, h int) Image {
 // write out a .ppm file
 fn (image Image) save_as_ppm(file_name string) {
 	npixels := image.width * image.height
-	mut f_out := os.create(file_name) or { panic(err.msg) }
-	f_out.writeln('P3') or { panic(err.msg) }
-	f_out.writeln('$image.width $image.height') or { panic(err.msg) }
-	f_out.writeln('255') or { panic(err.msg) }
+	mut f_out := os.create(file_name) or { panic(err) }
+	f_out.writeln('P3') or { panic(err) }
+	f_out.writeln('$image.width $image.height') or { panic(err) }
+	f_out.writeln('255') or { panic(err) }
 	for i in 0 .. npixels {
 		c_r := to_int(unsafe { image.data[i] }.x)
 		c_g := to_int(unsafe { image.data[i] }.y)
 		c_b := to_int(unsafe { image.data[i] }.z)
-		f_out.write_str('$c_r $c_g $c_b ') or { panic(err.msg) }
+		f_out.write_str('$c_r $c_g $c_b ') or { panic(err) }
 	}
 	f_out.close()
 }
diff --git a/examples/process/command.v b/examples/process/command.v
index d6cf12cb20..718ce96326 100644
--- a/examples/process/command.v
+++ b/examples/process/command.v
@@ -10,7 +10,7 @@ fn exec(path string) string {
 	mut cmd := os.Command{
 		path: path
 	}
-	cmd.start() or { panic(err.msg) }
+	cmd.start() or { panic(err) }
 
 	for {
 		line = cmd.read_line()
diff --git a/examples/process/execve.v b/examples/process/execve.v
index f8b611a7a9..f840c8dcd3 100644
--- a/examples/process/execve.v
+++ b/examples/process/execve.v
@@ -5,7 +5,7 @@ import os
 fn exec(args []string) {
 	os.execve('/bin/bash', args, []) or {
 		// eprintln(err)
-		panic(err.msg)
+		panic(err)
 	}
 }
 
diff --git a/examples/process/process_script.v b/examples/process/process_script.v
index 48d27abff2..fa415e7839 100644
--- a/examples/process/process_script.v
+++ b/examples/process/process_script.v
@@ -47,7 +47,7 @@ echo redirect 1 to 2  1>&2
 echo line 3
 '
 
-	os.write_file('/tmp/test.sh', script) or { panic(err.msg) }
+	os.write_file('/tmp/test.sh', script) or { panic(err) }
 	// os.chmod("/tmp/test.sh",0o700) //make executable
 
 	// this will work because stderr/stdout are smaller than 4096 chars, once larger there can be deadlocks
diff --git a/examples/regex/regex_example.v b/examples/regex/regex_example.v
index 00f7f3042b..7469ef5ade 100644
--- a/examples/regex/regex_example.v
+++ b/examples/regex/regex_example.v
@@ -25,7 +25,7 @@ fn convert_html_rgb(in_col string) u32 {
 
 	query := '#([a-fA-F0-9]{$n_digit})([a-fA-F0-9]{$n_digit})([a-fA-F0-9]{$n_digit})'
 
-	mut re := regex.regex_opt(query) or { panic(err.msg) }
+	mut re := regex.regex_opt(query) or { panic(err) }
 	start, end := re.match_string(in_col)
 	println('start: $start, end: $end')
 	mut res := u32(0)
@@ -49,7 +49,7 @@ fn convert_html_rgb_n(in_col string) u32 {
 
 	query := '#(?P<red>[a-fA-F0-9]{$n_digit})(?P<green>[a-fA-F0-9]{$n_digit})(?P<blue>[a-fA-F0-9]{$n_digit})'
 
-	mut re := regex.regex_opt(query) or { panic(err.msg) }
+	mut re := regex.regex_opt(query) or { panic(err) }
 	start, end := re.match_string(in_col)
 	println('start: $start, end: $end')
 	mut res := u32(0)
diff --git a/examples/templates/templates.v b/examples/templates/templates.v
index dbcea78303..a4917227af 100644
--- a/examples/templates/templates.v
+++ b/examples/templates/templates.v
@@ -171,12 +171,12 @@ fn data_get() []SiteConfig {
 
 fn data_dump(data []SiteConfig) {
 	a := json.encode_pretty(data)
-	os.write_file(os.resource_abs_path('data.json'), a) or { panic(err.msg) }
+	os.write_file(os.resource_abs_path('data.json'), a) or { panic(err) }
 }
 
 fn data_load() []SiteConfig {
-	data := os.read_file(os.resource_abs_path('data.json')) or { panic(err.msg) }
-	a := json.decode([]SiteConfig, data) or { panic(err.msg) }
+	data := os.read_file(os.resource_abs_path('data.json')) or { panic(err) }
+	a := json.decode([]SiteConfig, data) or { panic(err) }
 	return a
 }
 
@@ -192,5 +192,5 @@ fn main() {
 	// data_dump(data)
 	b := filled_in_template()
 	println(b)
-	os.write_file('result.md', b) or { panic(err.msg) }
+	os.write_file('result.md', b) or { panic(err) }
 }
diff --git a/examples/term.ui/text_editor.v b/examples/term.ui/text_editor.v
index 7431fbccfe..a08efa59be 100644
--- a/examples/term.ui/text_editor.v
+++ b/examples/term.ui/text_editor.v
@@ -44,7 +44,7 @@ fn (mut a App) set_status(msg string, duration_ms int) {
 fn (mut a App) save() {
 	if a.cfile().len > 0 {
 		b := a.ed
-		os.write_file(a.cfile(), b.raw()) or { panic(err.msg) }
+		os.write_file(a.cfile(), b.raw()) or { panic(err) }
 		a.set_status('Saved', 2000)
 	} else {
 		a.set_status('No file loaded', 4000)
@@ -456,7 +456,7 @@ fn (mut a App) init_file() {
 			// 'vico: ' +
 			a.tui.set_window_title(a.files[a.current_file])
 			mut b := a.ed
-			content := os.read_file(a.files[a.current_file]) or { panic(err.msg) }
+			content := os.read_file(a.files[a.current_file]) or { panic(err) }
 			b.put(content)
 			a.ed.cursor.pos_x = init_x
 			a.ed.cursor.pos_y = init_y
diff --git a/examples/ttf_font/example_ttf.v b/examples/ttf_font/example_ttf.v
index 16c2493f55..85eb26b00a 100644
--- a/examples/ttf_font/example_ttf.v
+++ b/examples/ttf_font/example_ttf.v
@@ -135,7 +135,7 @@ fn main() {
 	// load TTF fonts
 	for font_path in font_paths {
 		mut tf := ttf.TTF_File{}
-		tf.buf = os.read_bytes(font_path) or { panic(err.msg) }
+		tf.buf = os.read_bytes(font_path) or { panic(err) }
 		println('TrueTypeFont file [$font_path] len: $tf.buf.len')
 		tf.init()
 		println('Unit per EM: $tf.units_per_em')
diff --git a/examples/websocket/client-server/server.v b/examples/websocket/client-server/server.v
index e2cc352e45..154d2d44e5 100644
--- a/examples/websocket/client-server/server.v
+++ b/examples/websocket/client-server/server.v
@@ -28,7 +28,7 @@ fn start_server() ? {
 		for i, _ in m.clients {
 			mut c := m.clients[i]
 			if c.client.state == .open && c.client.id != ws.id {
-				c.client.write(msg.payload, websocket.OPCode.text_frame) or { panic(err.msg) }
+				c.client.write(msg.payload, websocket.OPCode.text_frame) or { panic(err) }
 			}
 		}
 	}, s)
diff --git a/examples/websocket/ping.v b/examples/websocket/ping.v
index 88aabb63b1..a68fa73c51 100644
--- a/examples/websocket/ping.v
+++ b/examples/websocket/ping.v
@@ -25,7 +25,7 @@ fn start_server() ? {
 		return true
 	}) ?
 	s.on_message(fn (mut ws websocket.Client, msg &websocket.Message) ? {
-		ws.write(msg.payload, msg.opcode) or { panic(err.msg) }
+		ws.write(msg.payload, msg.opcode) or { panic(err) }
 	})
 	s.on_close(fn (mut ws websocket.Client, code int, reason string) ? {
 		// println('client ($ws.id) closed connection')
diff --git a/tutorials/code/blog/blog.v b/tutorials/code/blog/blog.v
index 1889432a1d..c17a34de16 100644
--- a/tutorials/code/blog/blog.v
+++ b/tutorials/code/blog/blog.v
@@ -32,7 +32,7 @@ pub fn (app &App) index() vweb.Result {
 }
 
 pub fn (mut app App) init_once() {
-	app.db = sqlite.connect('blog.db') or { panic(err.msg) }
+	app.db = sqlite.connect('blog.db') or { panic(err) }
 	app.db.exec('create table if not exists article (' + 'id integer primary key, ' + "title text default ''," +
 		"text text default ''" + ');')
 }
diff --git a/vlib/builtin/bare/syscallwrapper_test.v b/vlib/builtin/bare/syscallwrapper_test.v
index 63022c90a1..b293978c8e 100644
--- a/vlib/builtin/bare/syscallwrapper_test.v
+++ b/vlib/builtin/bare/syscallwrapper_test.v
@@ -13,7 +13,7 @@ fn test_syscallwrappers() {
 				os.chdir(dot_checks)
 				checks_v := "checks.v"
 				assert os.exists(checks_v)
-				rc := os.exec("v run $checks_v") or { panic(err.msg) }
+				rc := os.exec("v run $checks_v") or { panic(err) }
 				assert !rc.output.contains("V panic: An assertion failed.")
 				assert !rc.output.contains("failed")
 				assert rc.exit_code == 0
diff --git a/vlib/cli/command.v b/vlib/cli/command.v
index ca917a50f0..6a66490b10 100644
--- a/vlib/cli/command.v
+++ b/vlib/cli/command.v
@@ -259,7 +259,7 @@ fn (cmd Command) check_version_flag() {
 		version_flag := cmd.flags.get_bool('version') or { return } // ignore error and handle command normally
 		if version_flag {
 			version_cmd := cmd.commands.get('version') or { return } // ignore error and handle command normally
-			version_cmd.execute(version_cmd) or { panic(err.msg) }
+			version_cmd.execute(version_cmd) or { panic(err) }
 			exit(0)
 		}
 	}
@@ -280,7 +280,7 @@ fn (cmd Command) check_required_flags() {
 pub fn (cmd Command) execute_help() {
 	if cmd.commands.contains('help') {
 		help_cmd := cmd.commands.get('help') or { return } // ignore error and handle command normally
-		help_cmd.execute(help_cmd) or { panic(err.msg) }
+		help_cmd.execute(help_cmd) or { panic(err) }
 	} else {
 		print(cmd.help_message())
 	}
diff --git a/vlib/cli/command_test.v b/vlib/cli/command_test.v
index 8e96802fb3..aae7199c85 100644
--- a/vlib/cli/command_test.v
+++ b/vlib/cli/command_test.v
@@ -135,7 +135,7 @@ fn test_if_required_flags_get_set() {
 }
 
 fn flag_is_set_in_subcommand(cmd cli.Command) ? {
-	flag := cmd.flags.get_string('flag') or { panic(err.msg) }
+	flag := cmd.flags.get_string('flag') or { panic(err) }
 	assert flag == 'value'
 }
 
diff --git a/vlib/cli/flag_test.v b/vlib/cli/flag_test.v
index 2fe533d837..7fb9a3f686 100644
--- a/vlib/cli/flag_test.v
+++ b/vlib/cli/flag_test.v
@@ -5,16 +5,16 @@ fn test_if_string_flag_parses() {
 		flag: .string
 		name: 'flag'
 	}
-	flag.parse(['-flag', 'value1'], false) or { panic(err.msg) }
-	mut value := flag.get_string() or { panic(err.msg) }
+	flag.parse(['-flag', 'value1'], false) or { panic(err) }
+	mut value := flag.get_string() or { panic(err) }
 	assert value == 'value1'
 
 	flag = cli.Flag{
 		flag: .string
 		name: 'flag'
 	}
-	flag.parse(['-flag=value2'], false) or { panic(err.msg) }
-	value = flag.get_string() or { panic(err.msg) }
+	flag.parse(['-flag=value2'], false) or { panic(err) }
+	value = flag.get_string() or { panic(err) }
 	assert value == 'value2'
 
 	flag = cli.Flag{
@@ -22,9 +22,9 @@ fn test_if_string_flag_parses() {
 		name: 'flag'
 		multiple: true
 	}
-	flag.parse(['-flag=value1'], false) or { panic(err.msg) }
-	flag.parse(['-flag=value2'], false) or { panic(err.msg) }
-	mut values := flag.get_strings() or { panic(err.msg) }
+	flag.parse(['-flag=value1'], false) or { panic(err) }
+	flag.parse(['-flag=value2'], false) or { panic(err) }
+	mut values := flag.get_strings() or { panic(err) }
 	assert values == ['value1', 'value2']
 
 	flags := [
@@ -40,7 +40,7 @@ fn test_if_string_flag_parses() {
 		},
 	]
 
-	values = flags.get_strings('flag') or { panic(err.msg) }
+	values = flags.get_strings('flag') or { panic(err) }
 	assert values == ['a', 'b', 'c']
 }
 
@@ -50,20 +50,20 @@ fn test_if_bool_flag_parses() {
 		name: 'flag'
 	}
 	mut value := false
-	flag.parse(['-flag'], false) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err.msg) }
+	flag.parse(['-flag'], false) or { panic(err) }
+	value = flag.get_bool() or { panic(err) }
 	assert value == true
-	flag.parse(['-flag', 'false'], false) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err.msg) }
+	flag.parse(['-flag', 'false'], false) or { panic(err) }
+	value = flag.get_bool() or { panic(err) }
 	assert value == false
-	flag.parse(['-flag', 'true'], false) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err.msg) }
+	flag.parse(['-flag', 'true'], false) or { panic(err) }
+	value = flag.get_bool() or { panic(err) }
 	assert value == true
-	flag.parse(['-flag=false'], false) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err.msg) }
+	flag.parse(['-flag=false'], false) or { panic(err) }
+	value = flag.get_bool() or { panic(err) }
 	assert value == false
-	flag.parse(['-flag=true'], false) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err.msg) }
+	flag.parse(['-flag=true'], false) or { panic(err) }
+	value = flag.get_bool() or { panic(err) }
 	assert value == true
 }
 
@@ -74,8 +74,8 @@ fn test_if_int_flag_parses() {
 	}
 
 	mut value := 0
-	flag.parse(['-flag', '42'], false) or { panic(err.msg) }
-	value = flag.get_int() or { panic(err.msg) }
+	flag.parse(['-flag', '42'], false) or { panic(err) }
+	value = flag.get_int() or { panic(err) }
 	assert value == 42
 
 	flag = cli.Flag{
@@ -83,8 +83,8 @@ fn test_if_int_flag_parses() {
 		name: 'flag'
 	}
 
-	flag.parse(['-flag=45'], false) or { panic(err.msg) }
-	value = flag.get_int() or { panic(err.msg) }
+	flag.parse(['-flag=45'], false) or { panic(err) }
+	value = flag.get_int() or { panic(err) }
 	assert value == 45
 
 	flag = cli.Flag{
@@ -93,9 +93,9 @@ fn test_if_int_flag_parses() {
 		multiple: true
 	}
 
-	flag.parse(['-flag=42'], false) or { panic(err.msg) }
-	flag.parse(['-flag=45'], false) or { panic(err.msg) }
-	mut values := flag.get_ints() or { panic(err.msg) }
+	flag.parse(['-flag=42'], false) or { panic(err) }
+	flag.parse(['-flag=45'], false) or { panic(err) }
+	mut values := flag.get_ints() or { panic(err) }
 	assert values == [42, 45]
 
 	flags := [
@@ -111,7 +111,7 @@ fn test_if_int_flag_parses() {
 		},
 	]
 
-	values = flags.get_ints('flag') or { panic(err.msg) }
+	values = flags.get_ints('flag') or { panic(err) }
 	assert values == [1, 2, 3]
 }
 
@@ -121,8 +121,8 @@ fn test_if_float_flag_parses() {
 		name: 'flag'
 	}
 	mut value := f64(0)
-	flag.parse(['-flag', '3.14158'], false) or { panic(err.msg) }
-	value = flag.get_float() or { panic(err.msg) }
+	flag.parse(['-flag', '3.14158'], false) or { panic(err) }
+	value = flag.get_float() or { panic(err) }
 	assert value == 3.14158
 
 	flag = cli.Flag{
@@ -130,9 +130,9 @@ fn test_if_float_flag_parses() {
 		name: 'flag'
 	}
 
-	flag.parse(['-flag=3.14159'], false) or { panic(err.msg) }
+	flag.parse(['-flag=3.14159'], false) or { panic(err) }
 	assert flag.value[0].f64() == 3.14159
-	value = flag.get_float() or { panic(err.msg) }
+	value = flag.get_float() or { panic(err) }
 	assert value == 3.14159
 
 	flag = cli.Flag{
@@ -141,9 +141,9 @@ fn test_if_float_flag_parses() {
 		multiple: true
 	}
 
-	flag.parse(['-flag=3.1'], false) or { panic(err.msg) }
-	flag.parse(['-flag=1.3'], false) or { panic(err.msg) }
-	mut values := flag.get_floats() or { panic(err.msg) }
+	flag.parse(['-flag=3.1'], false) or { panic(err) }
+	flag.parse(['-flag=1.3'], false) or { panic(err) }
+	mut values := flag.get_floats() or { panic(err) }
 	assert values == [3.1, 1.3]
 
 	flags := [
@@ -159,7 +159,7 @@ fn test_if_float_flag_parses() {
 		},
 	]
 
-	values = flags.get_floats('flag') or { panic(err.msg) }
+	values = flags.get_floats('flag') or { panic(err) }
 	assert values == [1.1, 2.2, 3.3]
 }
 
@@ -170,8 +170,8 @@ fn test_if_flag_parses_with_abbrev() {
 		abbrev: 'f'
 	}
 	mut value := false
-	flag.parse(['--flag'], true) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err.msg) }
+	flag.parse(['--flag'], true) or { panic(err) }
+	value = flag.get_bool() or { panic(err) }
 	assert value == true
 
 	value = false
@@ -180,8 +180,8 @@ fn test_if_flag_parses_with_abbrev() {
 		name: 'flag'
 		abbrev: 'f'
 	}
-	flag.parse(['-f'], true) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err.msg) }
+	flag.parse(['-f'], true) or { panic(err) }
+	value = flag.get_bool() or { panic(err) }
 	assert value == true
 }
 
@@ -191,7 +191,7 @@ fn test_if_multiple_value_on_single_value() {
 		name: 'flag'
 	}
 
-	flag.parse(['-flag', '3.14158'], false) or { panic(err.msg) }
+	flag.parse(['-flag', '3.14158'], false) or { panic(err) }
 
 	if _ := flag.parse(['-flag', '3.222'], false) {
 		panic("No multiple value flag don't raise an error!")
diff --git a/vlib/crypto/md5/md5.v b/vlib/crypto/md5/md5.v
index 923e4f169f..2d56d5513f 100644
--- a/vlib/crypto/md5/md5.v
+++ b/vlib/crypto/md5/md5.v
@@ -110,7 +110,7 @@ pub fn (mut d Digest) checksum() []byte {
 	tmp[0] = 0x80
 	pad := ((55 - d.len) % 64) // calculate number of padding bytes
 	binary.little_endian_put_u64(mut tmp[1 + pad..], d.len << 3) // append length in bits
-	d.write(tmp[..1 + pad + 8]) or { panic(err.msg) }
+	d.write(tmp[..1 + pad + 8]) or { panic(err) }
 	// The previous write ensures that a whole number of
 	// blocks (i.e. a multiple of 64 bytes) have been hashed.
 	if d.nx != 0 {
@@ -127,7 +127,7 @@ pub fn (mut d Digest) checksum() []byte {
 // sum returns the MD5 checksum of the data.
 pub fn sum(data []byte) []byte {
 	mut d := new()
-	d.write(data) or { panic(err.msg) }
+	d.write(data) or { panic(err) }
 	return d.checksum()
 }
 
diff --git a/vlib/crypto/sha1/sha1.v b/vlib/crypto/sha1/sha1.v
index eb3fb633a8..2e4b6fe66f 100644
--- a/vlib/crypto/sha1/sha1.v
+++ b/vlib/crypto/sha1/sha1.v
@@ -109,14 +109,14 @@ fn (mut d Digest) checksum() []byte {
 	mut tmp := []byte{len: (64)}
 	tmp[0] = 0x80
 	if int(len) % 64 < 56 {
-		d.write(tmp[..56 - int(len) % 64]) or { panic(err.msg) }
+		d.write(tmp[..56 - int(len) % 64]) or { panic(err) }
 	} else {
-		d.write(tmp[..64 + 56 - int(len) % 64]) or { panic(err.msg) }
+		d.write(tmp[..64 + 56 - int(len) % 64]) or { panic(err) }
 	}
 	// Length in bits.
 	len <<= 3
 	binary.big_endian_put_u64(mut tmp, len)
-	d.write(tmp[..8]) or { panic(err.msg) }
+	d.write(tmp[..8]) or { panic(err) }
 	mut digest := []byte{len: (size)}
 	binary.big_endian_put_u32(mut digest, d.h[0])
 	binary.big_endian_put_u32(mut digest[4..], d.h[1])
@@ -129,7 +129,7 @@ fn (mut d Digest) checksum() []byte {
 // sum returns the SHA-1 checksum of the bytes passed in `data`.
 pub fn sum(data []byte) []byte {
 	mut d := new()
-	d.write(data) or { panic(err.msg) }
+	d.write(data) or { panic(err) }
 	return d.checksum()
 }
 
diff --git a/vlib/crypto/sha256/sha256.v b/vlib/crypto/sha256/sha256.v
index 95795d58de..af37727c7d 100644
--- a/vlib/crypto/sha256/sha256.v
+++ b/vlib/crypto/sha256/sha256.v
@@ -147,14 +147,14 @@ fn (mut d Digest) checksum() []byte {
 	mut tmp := []byte{len: (64)}
 	tmp[0] = 0x80
 	if int(len) % 64 < 56 {
-		d.write(tmp[..56 - int(len) % 64]) or { panic(err.msg) }
+		d.write(tmp[..56 - int(len) % 64]) or { panic(err) }
 	} else {
-		d.write(tmp[..64 + 56 - int(len) % 64]) or { panic(err.msg) }
+		d.write(tmp[..64 + 56 - int(len) % 64]) or { panic(err) }
 	}
 	// Length in bits.
 	len <<= u64(3)
 	binary.big_endian_put_u64(mut tmp, len)
-	d.write(tmp[..8]) or { panic(err.msg) }
+	d.write(tmp[..8]) or { panic(err) }
 	if d.nx != 0 {
 		panic('d.nx != 0')
 	}
@@ -181,14 +181,14 @@ pub fn sum(data []byte) []byte {
 // sum256 returns the SHA256 checksum of the data.
 pub fn sum256(data []byte) []byte {
 	mut d := new()
-	d.write(data) or { panic(err.msg) }
+	d.write(data) or { panic(err) }
 	return d.checksum()
 }
 
 // sum224 returns the SHA224 checksum of the data.
 pub fn sum224(data []byte) []byte {
 	mut d := new224()
-	d.write(data) or { panic(err.msg) }
+	d.write(data) or { panic(err) }
 	sum := d.checksum()
 	sum224 := []byte{len: (size224)}
 	copy(sum224, sum[..size224])
diff --git a/vlib/crypto/sha512/sha512.v b/vlib/crypto/sha512/sha512.v
index 7f972243cb..0ddff114e1 100644
--- a/vlib/crypto/sha512/sha512.v
+++ b/vlib/crypto/sha512/sha512.v
@@ -219,15 +219,15 @@ fn (mut d Digest) checksum() []byte {
 	mut tmp := []byte{len: (128)}
 	tmp[0] = 0x80
 	if int(len) % 128 < 112 {
-		d.write(tmp[..112 - int(len) % 128]) or { panic(err.msg) }
+		d.write(tmp[..112 - int(len) % 128]) or { panic(err) }
 	} else {
-		d.write(tmp[..128 + 112 - int(len) % 128]) or { panic(err.msg) }
+		d.write(tmp[..128 + 112 - int(len) % 128]) or { panic(err) }
 	}
 	// Length in bits.
 	len <<= u64(3)
 	binary.big_endian_put_u64(mut tmp, u64(0)) // upper 64 bits are always zero, because len variable has type u64
 	binary.big_endian_put_u64(mut tmp[8..], len)
-	d.write(tmp[..16]) or { panic(err.msg) }
+	d.write(tmp[..16]) or { panic(err) }
 	if d.nx != 0 {
 		panic('d.nx != 0')
 	}
@@ -248,14 +248,14 @@ fn (mut d Digest) checksum() []byte {
 // sum512 returns the SHA512 checksum of the data.
 pub fn sum512(data []byte) []byte {
 	mut d := new_digest(.sha512)
-	d.write(data) or { panic(err.msg) }
+	d.write(data) or { panic(err) }
 	return d.checksum()
 }
 
 // sum384 returns the SHA384 checksum of the data.
 pub fn sum384(data []byte) []byte {
 	mut d := new_digest(.sha384)
-	d.write(data) or { panic(err.msg) }
+	d.write(data) or { panic(err) }
 	sum := d.checksum()
 	sum384 := []byte{len: (size384)}
 	copy(sum384, sum[..size384])
@@ -265,7 +265,7 @@ pub fn sum384(data []byte) []byte {
 // sum512_224 returns the Sum512/224 checksum of the data.
 pub fn sum512_224(data []byte) []byte {
 	mut d := new_digest(.sha512_224)
-	d.write(data) or { panic(err.msg) }
+	d.write(data) or { panic(err) }
 	sum := d.checksum()
 	sum224 := []byte{len: (size224)}
 	copy(sum224, sum[..size224])
@@ -275,7 +275,7 @@ pub fn sum512_224(data []byte) []byte {
 // sum512_256 returns the Sum512/256 checksum of the data.
 pub fn sum512_256(data []byte) []byte {
 	mut d := new_digest(.sha512_256)
-	d.write(data) or { panic(err.msg) }
+	d.write(data) or { panic(err) }
 	sum := d.checksum()
 	sum256 := []byte{len: (size256)}
 	copy(sum256, sum[..size256])
diff --git a/vlib/dl/example/use_test.v b/vlib/dl/example/use_test.v
index 9bb7396fe2..812281d8a2 100644
--- a/vlib/dl/example/use_test.v
+++ b/vlib/dl/example/use_test.v
@@ -40,7 +40,7 @@ fn test_can_compile_main_program() {
 fn v_compile(vopts string) os.Result {
 	cmd := '"$vexe" -showcc $vopts'
 	eprintln('>>> v_compile cmd: $cmd')
-	res := os.exec(cmd) or { panic(err.msg) }
+	res := os.exec(cmd) or { panic(err) }
 	eprintln('>>> v_compile res: $res')
 	// assert res.exit_code == 0
 	$if !windows {
diff --git a/vlib/gg/gg.v b/vlib/gg/gg.v
index 45ca1e9b2b..59d90af7d3 100644
--- a/vlib/gg/gg.v
+++ b/vlib/gg/gg.v
@@ -162,7 +162,7 @@ fn gg_init_sokol_window(user_data voidptr) {
 			font_path: g.config.font_path
 			custom_bold_font_path: g.config.custom_bold_font_path
 			scale: dpi_scale()
-		) or { panic(err.msg) }
+		) or { panic(err) }
 		// println('FT took ${time.ticks()-t} ms')
 		g.font_inited = true
 	} else {
@@ -174,7 +174,7 @@ fn gg_init_sokol_window(user_data voidptr) {
 					bytes_mono: g.config.font_bytes_mono
 					bytes_italic: g.config.font_bytes_italic
 					scale: sapp.dpi_scale()
-				) or { panic(err.msg) }
+				) or { panic(err) }
 				g.font_inited = true
 			} else {
 				sfont := system_font_path()
@@ -183,7 +183,7 @@ fn gg_init_sokol_window(user_data voidptr) {
 					font_path: sfont
 					custom_bold_font_path: g.config.custom_bold_font_path
 					scale: sapp.dpi_scale()
-				) or { panic(err.msg) }
+				) or { panic(err) }
 				g.font_inited = true
 			}
 		}
diff --git a/vlib/io/os_file_reader_test.v b/vlib/io/os_file_reader_test.v
index c59465f8ff..39606c8a03 100644
--- a/vlib/io/os_file_reader_test.v
+++ b/vlib/io/os_file_reader_test.v
@@ -3,7 +3,7 @@ import io
 
 fn read_file(file string, cap int) []string {
 	mut lines := []string{}
-	mut f := os.open(file) or { panic(err.msg) }
+	mut f := os.open(file) or { panic(err) }
 	defer {
 		f.close()
 	}
diff --git a/vlib/io/util/util_test.v b/vlib/io/util/util_test.v
index 64686efe52..ff09e7e5dd 100644
--- a/vlib/io/util/util_test.v
+++ b/vlib/io/util/util_test.v
@@ -12,7 +12,7 @@ fn testsuite_begin() {
 	eprintln('testsuite_begin, tfolder = $tfolder')
 	os.rmdir_all(tfolder) or { }
 	assert !os.is_dir(tfolder)
-	os.mkdir_all(tfolder) or { panic(err.msg) }
+	os.mkdir_all(tfolder) or { panic(err) }
 	os.chdir(tfolder)
 	assert os.is_dir(tfolder)
 }
diff --git a/vlib/json/json_test.v b/vlib/json/json_test.v
index 0b1a0ca2ff..428b50455e 100644
--- a/vlib/json/json_test.v
+++ b/vlib/json/json_test.v
@@ -370,7 +370,7 @@ struct Info {
 }
 
 fn test_decode_null_object() {
-	info := json.decode(Info, '{"id": 22, "items": null, "maps": null}') or { panic(err.msg) }
+	info := json.decode(Info, '{"id": 22, "items": null, "maps": null}') or { panic(err) }
 	assert info.id == 22
 	assert '$info.items' == '[]'
 	assert '$info.maps' == '{}'
diff --git a/vlib/log/log.v b/vlib/log/log.v
index a5ce5f7290..4ba9e5e45e 100644
--- a/vlib/log/log.v
+++ b/vlib/log/log.v
@@ -106,7 +106,7 @@ pub fn (mut l Log) close() {
 fn (mut l Log) log_file(s string, level Level) {
 	timestamp := time.now().format_ss()
 	e := tag_to_file(level)
-	l.ofile.writeln('$timestamp [$e] $s') or { panic(err.msg) }
+	l.ofile.writeln('$timestamp [$e] $s') or { panic(err) }
 }
 
 // log_cli writes log line `s` with `level` to stdout.
diff --git a/vlib/net/ftp/ftp.v b/vlib/net/ftp/ftp.v
index 8fab97a5f5..f27ebb537a 100644
--- a/vlib/net/ftp/ftp.v
+++ b/vlib/net/ftp/ftp.v
@@ -56,7 +56,7 @@ fn (mut dtp DTP) read() ?[]byte {
 }
 
 fn (mut dtp DTP) close() {
-	dtp.conn.close() or { panic(err.msg) }
+	dtp.conn.close() or { panic(err) }
 }
 
 struct FTP {
diff --git a/vlib/net/ftp/ftp_test.v b/vlib/net/ftp/ftp_test.v
index a98ff88975..a62316d00c 100644
--- a/vlib/net/ftp/ftp_test.v
+++ b/vlib/net/ftp/ftp_test.v
@@ -8,14 +8,14 @@ fn test_ftp_cleint() {
 	// that is why it is not a very good idea to run it in CI.
 	// If you want to run it manually, use:
 	// `v -d network vlib/net/ftp/ftp_test.v`
-	ftp_client_test_inside() or { panic(err.msg) }
+	ftp_client_test_inside() or { panic(err) }
 }
 
 fn ftp_client_test_inside() ? {
 	mut zftp := ftp.new()
 	// eprintln(zftp)
 	defer {
-		zftp.close() or { panic(err.msg) }
+		zftp.close() or { panic(err) }
 	}
 	connect_result := zftp.connect('ftp.redhat.com') ?
 	assert connect_result
diff --git a/vlib/net/html/dom.v b/vlib/net/html/dom.v
index 25921c38b4..f56e9c2dc3 100644
--- a/vlib/net/html/dom.v
+++ b/vlib/net/html/dom.v
@@ -25,7 +25,7 @@ mut:
 fn (mut dom DocumentObjectModel) print_debug(data string) {
 	$if debug {
 		if data.len > 0 {
-			dom.debug_file.writeln(data) or { panic(err.msg) }
+			dom.debug_file.writeln(data) or { panic(err) }
 		}
 	}
 }
diff --git a/vlib/net/html/parser.v b/vlib/net/html/parser.v
index a26826c8b2..ac6e97e5d4 100644
--- a/vlib/net/html/parser.v
+++ b/vlib/net/html/parser.v
@@ -53,7 +53,7 @@ fn (parser Parser) builder_str() string {
 fn (mut parser Parser) print_debug(data string) {
 	$if debug {
 		if data.len > 0 {
-			parser.debug_file.writeln(data) or { panic(err.msg) }
+			parser.debug_file.writeln(data) or { panic(err) }
 		}
 	}
 }
diff --git a/vlib/net/http/http_httpbin_test.v b/vlib/net/http/http_httpbin_test.v
index 38520043b7..cbdfcd009d 100644
--- a/vlib/net/http/http_httpbin_test.v
+++ b/vlib/net/http/http_httpbin_test.v
@@ -34,7 +34,7 @@ fn http_fetch_mock(_methods []string, _config FetchConfig) ?[]Response {
 fn test_http_fetch_bare() {
 	$if !network ? { return }
 	responses := http_fetch_mock([], FetchConfig{}) or {
-		panic(err.msg)
+		panic(err)
 	}
 	for response in responses {
 		assert response.status_code == 200
@@ -46,11 +46,11 @@ fn test_http_fetch_with_data() {
 	responses := http_fetch_mock(['POST', 'PUT', 'PATCH', 'DELETE'], {
 		data: 'hello world'
 	}) or {
-		panic(err.msg)
+		panic(err)
 	}
 	for response in responses {
 		payload := json.decode(HttpbinResponseBody,response.text) or {
-			panic(err.msg)
+			panic(err)
 		}
 		assert payload.data == 'hello world'
 	}
@@ -64,11 +64,11 @@ fn test_http_fetch_with_params() {
 			'c': 'd'
 		}
 	}) or {
-		panic(err.msg)
+		panic(err)
 	}
 	for response in responses {
 		// payload := json.decode(HttpbinResponseBody,response.text) or {
-		// panic(err.msg)
+		// panic(err)
 		// }
 		assert response.status_code == 200
 		// TODO
@@ -84,11 +84,11 @@ fn test_http_fetch_with_headers() {
 			'Test-Header': 'hello world'
 		}
 	}) or {
-		panic(err.msg)
+		panic(err)
 	}
 	for response in responses {
 		// payload := json.decode(HttpbinResponseBody,response.text) or {
-		// panic(err.msg)
+		// panic(err)
 		// }
 		assert response.status_code == 200
 		// TODO
diff --git a/vlib/net/http/http_test.v b/vlib/net/http/http_test.v
index 0ec8e7eb45..adc1c0aab6 100644
--- a/vlib/net/http/http_test.v
+++ b/vlib/net/http/http_test.v
@@ -16,7 +16,7 @@ fn test_http_get_from_vlang_utc_now() {
 	for url in urls {
 		println('Test getting current time from $url by http.get')
 		res := http.get(url) or {
-			panic(err.msg)
+			panic(err)
 		}
 		assert 200 == res.status_code
 		assert res.text.len > 0
@@ -40,7 +40,7 @@ fn test_public_servers() {
 	for url in urls {
 		println('Testing http.get on public url: $url ')
 		res := http.get(url) or {
-			panic(err.msg)
+			panic(err)
 		}
 		assert 200 == res.status_code
 		assert res.text.len > 0
@@ -54,7 +54,7 @@ fn test_relative_redirects() {
 		return
 	} // tempfix periodic: httpbin relative redirects are broken
 	res := http.get('https://httpbin.org/relative-redirect/3?abc=xyz') or {
-		panic(err.msg)
+		panic(err)
 	}
 	assert 200 == res.status_code
 	assert res.text.len > 0
diff --git a/vlib/net/tcp_simple_client_server_test.v b/vlib/net/tcp_simple_client_server_test.v
index 6e95cdc216..dffe45edf3 100644
--- a/vlib/net/tcp_simple_client_server_test.v
+++ b/vlib/net/tcp_simple_client_server_test.v
@@ -7,9 +7,9 @@ const (
 )
 
 fn setup() (&net.TcpListener, &net.TcpConn, &net.TcpConn) {
-	mut server := net.listen_tcp(server_port) or { panic(err.msg) }
-	mut client := net.dial_tcp('127.0.0.1:$server_port') or { panic(err.msg) }
-	mut socket := server.accept() or { panic(err.msg) }
+	mut server := net.listen_tcp(server_port) or { panic(err) }
+	mut client := net.dial_tcp('127.0.0.1:$server_port') or { panic(err) }
+	mut socket := server.accept() or { panic(err) }
 	$if debug_peer_ip ? {
 		ip := con.peer_ip() or { '$err' }
 		eprintln('connection peer_ip: $ip')
diff --git a/vlib/net/tcp_test.v b/vlib/net/tcp_test.v
index 5a0988d389..557300c73d 100644
--- a/vlib/net/tcp_test.v
+++ b/vlib/net/tcp_test.v
@@ -44,8 +44,8 @@ fn echo() ? {
 }
 
 fn test_tcp() {
-	mut l := net.listen_tcp(test_port) or { panic(err.msg) }
+	mut l := net.listen_tcp(test_port) or { panic(err) }
 	go echo_server(mut l)
-	echo() or { panic(err.msg) }
+	echo() or { panic(err) }
 	l.close() or { }
 }
diff --git a/vlib/net/unix/unix_test.v b/vlib/net/unix/unix_test.v
index 4177031019..2b5ffce6c6 100644
--- a/vlib/net/unix/unix_test.v
+++ b/vlib/net/unix/unix_test.v
@@ -51,8 +51,8 @@ fn echo() ? {
 }
 
 fn test_tcp() {
-	mut l := unix.listen_stream(test_port) or { panic(err.msg) }
+	mut l := unix.listen_stream(test_port) or { panic(err) }
 	go echo_server(mut l)
-	echo() or { panic(err.msg) }
+	echo() or { panic(err) }
 	l.close() or { }
 }
diff --git a/vlib/orm/orm_test.v b/vlib/orm/orm_test.v
index 7a2be7e8ca..e29d4435e1 100644
--- a/vlib/orm/orm_test.v
+++ b/vlib/orm/orm_test.v
@@ -22,7 +22,7 @@ struct Foo {
 }
 
 fn test_orm_sqlite() {
-	db := sqlite.connect(':memory:') or { panic(err.msg) }
+	db := sqlite.connect(':memory:') or { panic(err) }
 	db.exec('drop table if exists User')
 	db.exec("create table User (id integer primary key, age int default 0, name text default '', is_customer int default 0);")
 	name := 'Peter'
@@ -230,7 +230,7 @@ fn test_orm_pg() {
 		eprintln(term.red('NB: this test requires VDB_NAME and VDB_USER env variables to be set'))
 		return
 	}
-	db := pg.connect(dbname: dbname, user: dbuser) or { panic(err.msg) }
+	db := pg.connect(dbname: dbname, user: dbuser) or { panic(err) }
 	_ = db
 	nr_modules := db.select count from modules
 	//nr_modules := db.select count from Modules where id == 1
diff --git a/vlib/os/inode_test.v b/vlib/os/inode_test.v
index 1227037205..395756e228 100644
--- a/vlib/os/inode_test.v
+++ b/vlib/os/inode_test.v
@@ -11,14 +11,14 @@ fn testsuite_begin() {
 	eprintln('testsuite_begin, tfolder = $tfolder')
 	os.rmdir_all(tfolder) or { }
 	assert !os.is_dir(tfolder)
-	os.mkdir_all(tfolder) or { panic(err.msg) }
+	os.mkdir_all(tfolder) or { panic(err) }
 	os.chdir(tfolder)
 	assert os.is_dir(tfolder)
 }
 
 fn testsuite_end() {
 	os.chdir(os.wd_at_startup)
-	os.rmdir_all(tfolder) or { panic(err.msg) }
+	os.rmdir_all(tfolder) or { panic(err) }
 	assert !os.is_dir(tfolder)
 }
 
@@ -27,7 +27,7 @@ fn test_inode_file_type() {
 	mut file := os.open_file(filename, 'w', 0o600) or { return }
 	file.close()
 	mode := os.inode(filename)
-	os.rm(filename) or { panic(err.msg) }
+	os.rm(filename) or { panic(err) }
 	assert mode.typ == .regular
 }
 
diff --git a/vlib/os/os.v b/vlib/os/os.v
index e762c365bc..b2011fe351 100644
--- a/vlib/os/os.v
+++ b/vlib/os/os.v
@@ -507,7 +507,7 @@ pub fn cache_dir() string {
 	}
 	cdir := join_path(home_dir(), '.cache')
 	if !is_dir(cdir) && !is_link(cdir) {
-		mkdir(cdir) or { panic(err.msg) }
+		mkdir(cdir) or { panic(err) }
 	}
 	return cdir
 }
diff --git a/vlib/os/os_test.v b/vlib/os/os_test.v
index 1f5e1efaa5..141df342a6 100644
--- a/vlib/os/os_test.v
+++ b/vlib/os/os_test.v
@@ -15,7 +15,7 @@ fn testsuite_begin() {
 	eprintln('testsuite_begin, tfolder = $tfolder')
 	os.rmdir_all(tfolder) or { }
 	assert !os.is_dir(tfolder)
-	os.mkdir_all(tfolder) or { panic(err.msg) }
+	os.mkdir_all(tfolder) or { panic(err) }
 	os.chdir(tfolder)
 	assert os.is_dir(tfolder)
 	// println('args_at_start: $args_at_start')
@@ -37,13 +37,13 @@ fn test_open_file() {
 		assert err.msg == 'No such file or directory'
 		os.File{}
 	}
-	mut file := os.open_file(filename, 'w+', 0o666) or { panic(err.msg) }
-	file.write_str(hello) or { panic(err.msg) }
+	mut file := os.open_file(filename, 'w+', 0o666) or { panic(err) }
+	file.write_str(hello) or { panic(err) }
 	file.close()
 	assert hello.len == os.file_size(filename)
 	read_hello := os.read_file(filename) or { panic('error reading file $filename') }
 	assert hello == read_hello
-	os.rm(filename) or { panic(err.msg) }
+	os.rm(filename) or { panic(err) }
 }
 
 fn test_open_file_binary() {
@@ -53,14 +53,14 @@ fn test_open_file_binary() {
 		assert err.msg == 'No such file or directory'
 		os.File{}
 	}
-	mut file := os.open_file(filename, 'wb+', 0o666) or { panic(err.msg) }
+	mut file := os.open_file(filename, 'wb+', 0o666) or { panic(err) }
 	bytes := hello.bytes()
 	file.write_bytes(bytes.data, bytes.len)
 	file.close()
 	assert hello.len == os.file_size(filename)
 	read_hello := os.read_bytes(filename) or { panic('error reading file $filename') }
 	assert bytes == read_hello
-	os.rm(filename) or { panic(err.msg) }
+	os.rm(filename) or { panic(err) }
 }
 
 // fn test_file_get_line() {
@@ -86,24 +86,24 @@ fn test_open_file_binary() {
 fn test_create_file() {
 	filename := './test1.txt'
 	hello := 'hello world!'
-	mut f := os.create(filename) or { panic(err.msg) }
-	f.write_str(hello) or { panic(err.msg) }
+	mut f := os.create(filename) or { panic(err) }
+	f.write_str(hello) or { panic(err) }
 	f.close()
 	assert hello.len == os.file_size(filename)
-	os.rm(filename) or { panic(err.msg) }
+	os.rm(filename) or { panic(err) }
 }
 
 fn test_is_file() {
 	// Setup
 	work_dir := os.join_path(os.getwd(), 'is_file_test')
-	os.mkdir_all(work_dir) or { panic(err.msg) }
+	os.mkdir_all(work_dir) or { panic(err) }
 	tfile := os.join_path(work_dir, 'tmp_file')
 	// Test things that shouldn't be a file
 	assert os.is_file(work_dir) == false
 	assert os.is_file('non-existent_file.tmp') == false
 	// Test file
 	tfile_content := 'temporary file'
-	os.write_file(tfile, tfile_content) or { panic(err.msg) }
+	os.write_file(tfile, tfile_content) or { panic(err) }
 	assert os.is_file(tfile)
 	// Test dir symlinks
 	$if windows {
@@ -126,11 +126,11 @@ fn test_is_file() {
 fn test_write_and_read_string_to_file() {
 	filename := './test1.txt'
 	hello := 'hello world!'
-	os.write_file(filename, hello) or { panic(err.msg) }
+	os.write_file(filename, hello) or { panic(err) }
 	assert hello.len == os.file_size(filename)
 	read_hello := os.read_file(filename) or { panic('error reading file $filename') }
 	assert hello == read_hello
-	os.rm(filename) or { panic(err.msg) }
+	os.rm(filename) or { panic(err) }
 }
 
 // test_write_and_read_bytes checks for regressions made in the functions
@@ -166,16 +166,16 @@ fn test_write_and_read_bytes() {
 	assert nread == 0
 	file_read.close()
 	// We finally delete the test file.
-	os.rm(file_name) or { panic(err.msg) }
+	os.rm(file_name) or { panic(err) }
 }
 
 fn test_create_and_delete_folder() {
 	folder := './test1'
-	os.mkdir(folder) or { panic(err.msg) }
+	os.mkdir(folder) or { panic(err) }
 	assert os.is_dir(folder)
-	folder_contents := os.ls(folder) or { panic(err.msg) }
+	folder_contents := os.ls(folder) or { panic(err) }
 	assert folder_contents.len == 0
-	os.rmdir(folder) or { panic(err.msg) }
+	os.rmdir(folder) or { panic(err) }
 	folder_exists := os.is_dir(folder)
 	assert folder_exists == false
 }
@@ -189,63 +189,63 @@ fn walk_callback(file string) {
 
 fn test_walk() {
 	folder := 'test_walk'
-	os.mkdir(folder) or { panic(err.msg) }
+	os.mkdir(folder) or { panic(err) }
 	file1 := folder + os.path_separator + 'test1'
-	os.write_file(file1, 'test-1') or { panic(err.msg) }
+	os.write_file(file1, 'test-1') or { panic(err) }
 	os.walk(folder, walk_callback)
-	os.rm(file1) or { panic(err.msg) }
-	os.rmdir(folder) or { panic(err.msg) }
+	os.rm(file1) or { panic(err) }
+	os.rmdir(folder) or { panic(err) }
 }
 
 fn test_cp() {
 	old_file_name := 'cp_example.txt'
 	new_file_name := 'cp_new_example.txt'
-	os.write_file(old_file_name, 'Test data 1 2 3, V is awesome #$%^[]!~⭐') or { panic(err.msg) }
+	os.write_file(old_file_name, 'Test data 1 2 3, V is awesome #$%^[]!~⭐') or { panic(err) }
 	os.cp(old_file_name, new_file_name) or { panic('$err') }
-	old_file := os.read_file(old_file_name) or { panic(err.msg) }
-	new_file := os.read_file(new_file_name) or { panic(err.msg) }
+	old_file := os.read_file(old_file_name) or { panic(err) }
+	new_file := os.read_file(new_file_name) or { panic(err) }
 	assert old_file == new_file
-	os.rm(old_file_name) or { panic(err.msg) }
-	os.rm(new_file_name) or { panic(err.msg) }
+	os.rm(old_file_name) or { panic(err) }
+	os.rm(new_file_name) or { panic(err) }
 }
 
 fn test_mv() {
 	work_dir := os.join_path(os.getwd(), 'mv_test')
-	os.mkdir_all(work_dir) or { panic(err.msg) }
+	os.mkdir_all(work_dir) or { panic(err) }
 	// Setup test files
 	tfile1 := os.join_path(work_dir, 'file')
 	tfile2 := os.join_path(work_dir, 'file.test')
 	tfile3 := os.join_path(work_dir, 'file.3')
 	tfile_content := 'temporary file'
-	os.write_file(tfile1, tfile_content) or { panic(err.msg) }
-	os.write_file(tfile2, tfile_content) or { panic(err.msg) }
+	os.write_file(tfile1, tfile_content) or { panic(err) }
+	os.write_file(tfile2, tfile_content) or { panic(err) }
 	// Setup test dirs
 	tdir1 := os.join_path(work_dir, 'dir')
 	tdir2 := os.join_path(work_dir, 'dir2')
 	tdir3 := os.join_path(work_dir, 'dir3')
-	os.mkdir(tdir1) or { panic(err.msg) }
-	os.mkdir(tdir2) or { panic(err.msg) }
+	os.mkdir(tdir1) or { panic(err) }
+	os.mkdir(tdir2) or { panic(err) }
 	// Move file with no extension to dir
-	os.mv(tfile1, tdir1) or { panic(err.msg) }
+	os.mv(tfile1, tdir1) or { panic(err) }
 	mut expected := os.join_path(tdir1, 'file')
 	assert os.exists(expected) && !is_dir(expected) == true
 	// Move dir with contents to other dir
-	os.mv(tdir1, tdir2) or { panic(err.msg) }
+	os.mv(tdir1, tdir2) or { panic(err) }
 	expected = os.join_path(tdir2, 'dir')
 	assert os.exists(expected) && is_dir(expected) == true
 	expected = os.join_path(tdir2, 'dir', 'file')
 	assert os.exists(expected) && !is_dir(expected) == true
 	// Move dir with contents to other dir (by renaming)
-	os.mv(os.join_path(tdir2, 'dir'), tdir3) or { panic(err.msg) }
+	os.mv(os.join_path(tdir2, 'dir'), tdir3) or { panic(err) }
 	expected = tdir3
 	assert os.exists(expected) && is_dir(expected) == true
 	assert os.is_dir_empty(tdir2) == true
 	// Move file with extension to dir
-	os.mv(tfile2, tdir2) or { panic(err.msg) }
+	os.mv(tfile2, tdir2) or { panic(err) }
 	expected = os.join_path(tdir2, 'file.test')
 	assert os.exists(expected) && !is_dir(expected) == true
 	// Move file to dir (by renaming)
-	os.mv(os.join_path(tdir2, 'file.test'), tfile3) or { panic(err.msg) }
+	os.mv(os.join_path(tdir2, 'file.test'), tfile3) or { panic(err) }
 	expected = tfile3
 	assert os.exists(expected) && !is_dir(expected) == true
 }
@@ -253,22 +253,22 @@ fn test_mv() {
 fn test_cp_all() {
 	// fileX -> dir/fileX
 	// NB: clean up of the files happens inside the cleanup_leftovers function
-	os.write_file('ex1.txt', 'wow!') or { panic(err.msg) }
-	os.mkdir('ex') or { panic(err.msg) }
-	os.cp_all('ex1.txt', 'ex', false) or { panic(err.msg) }
-	old := os.read_file('ex1.txt') or { panic(err.msg) }
-	new := os.read_file('ex/ex1.txt') or { panic(err.msg) }
+	os.write_file('ex1.txt', 'wow!') or { panic(err) }
+	os.mkdir('ex') or { panic(err) }
+	os.cp_all('ex1.txt', 'ex', false) or { panic(err) }
+	old := os.read_file('ex1.txt') or { panic(err) }
+	new := os.read_file('ex/ex1.txt') or { panic(err) }
 	assert old == new
-	os.mkdir('ex/ex2') or { panic(err.msg) }
-	os.write_file('ex2.txt', 'great!') or { panic(err.msg) }
-	os.cp_all('ex2.txt', 'ex/ex2', false) or { panic(err.msg) }
-	old2 := os.read_file('ex2.txt') or { panic(err.msg) }
-	new2 := os.read_file('ex/ex2/ex2.txt') or { panic(err.msg) }
+	os.mkdir('ex/ex2') or { panic(err) }
+	os.write_file('ex2.txt', 'great!') or { panic(err) }
+	os.cp_all('ex2.txt', 'ex/ex2', false) or { panic(err) }
+	old2 := os.read_file('ex2.txt') or { panic(err) }
+	new2 := os.read_file('ex/ex2/ex2.txt') or { panic(err) }
 	assert old2 == new2
 	// recurring on dir -> local dir
-	os.cp_all('ex', './', true) or { panic(err.msg) }
+	os.cp_all('ex', './', true) or { panic(err) }
 	// regression test for executive runs with overwrite := true
-	os.cp_all('ex', './', true) or { panic(err.msg) }
+	os.cp_all('ex', './', true) or { panic(err) }
 }
 
 fn test_realpath() {
@@ -282,10 +282,10 @@ fn test_tmpdir() {
 	tfile := t + os.path_separator + 'tmpfile.txt'
 	os.rm(tfile) or { } // just in case
 	tfile_content := 'this is a temporary file'
-	os.write_file(tfile, tfile_content) or { panic(err.msg) }
-	tfile_content_read := os.read_file(tfile) or { panic(err.msg) }
+	os.write_file(tfile, tfile_content) or { panic(err) }
+	tfile_content_read := os.read_file(tfile) or { panic(err) }
 	assert tfile_content_read == tfile_content
-	os.rm(tfile) or { panic(err.msg) }
+	os.rm(tfile) or { panic(err) }
 }
 
 fn test_is_writable_folder() {
@@ -307,13 +307,13 @@ fn test_make_symlink_check_is_link_and_remove_symlink() {
 	symlink := 'tsymlink'
 	os.rm(symlink) or { }
 	os.rm(folder) or { }
-	os.mkdir(folder) or { panic(err.msg) }
-	folder_contents := os.ls(folder) or { panic(err.msg) }
+	os.mkdir(folder) or { panic(err) }
+	folder_contents := os.ls(folder) or { panic(err) }
 	assert folder_contents.len == 0
 	os.system('ln -s $folder $symlink')
 	assert os.is_link(symlink) == true
-	os.rm(symlink) or { panic(err.msg) }
-	os.rm(folder) or { panic(err.msg) }
+	os.rm(symlink) or { panic(err) }
+	os.rm(folder) or { panic(err) }
 	folder_exists := os.is_dir(folder)
 	assert folder_exists == false
 	symlink_exists := os.is_link(symlink)
@@ -345,12 +345,12 @@ fn test_symlink() {
 	$if windows {
 		return
 	}
-	os.mkdir('symlink') or { panic(err.msg) }
-	os.symlink('symlink', 'symlink2') or { panic(err.msg) }
+	os.mkdir('symlink') or { panic(err) }
+	os.symlink('symlink', 'symlink2') or { panic(err) }
 	assert os.exists('symlink2')
 	// cleanup
-	os.rm('symlink') or { panic(err.msg) }
-	os.rm('symlink2') or { panic(err.msg) }
+	os.rm('symlink') or { panic(err) }
+	os.rm('symlink2') or { panic(err) }
 }
 
 fn test_is_executable_writable_readable() {
@@ -373,7 +373,7 @@ fn test_is_executable_writable_readable() {
 		assert os.is_executable(file_name)
 	}
 	// We finally delete the test file.
-	os.rm(file_name) or { panic(err.msg) }
+	os.rm(file_name) or { panic(err) }
 }
 
 fn test_ext() {
@@ -457,8 +457,8 @@ fn test_write_file_array_bytes() {
 	for i in 0 .. maxn {
 		arr[i] = 65 + byte(i)
 	}
-	os.write_file_array(fpath, arr) or { panic(err.msg) }
-	rarr := os.read_bytes(fpath) or { panic(err.msg) }
+	os.write_file_array(fpath, arr) or { panic(err) }
+	rarr := os.read_bytes(fpath) or { panic(err) }
 	assert arr == rarr
 	// eprintln(arr.str())
 	// eprintln(rarr.str())
@@ -470,7 +470,7 @@ fn test_write_file_array_structs() {
 	for i in 0 .. maxn {
 		arr[i] = IntPoint{65 + i, 65 + i + 10}
 	}
-	os.write_file_array(fpath, arr) or { panic(err.msg) }
+	os.write_file_array(fpath, arr) or { panic(err) }
 	rarr := os.read_file_array<IntPoint>(fpath)
 	assert rarr == arr
 	assert rarr.len == maxn
diff --git a/vlib/readline/readline_test.v b/vlib/readline/readline_test.v
index e50964657e..ab5154f38d 100644
--- a/vlib/readline/readline_test.v
+++ b/vlib/readline/readline_test.v
@@ -7,7 +7,7 @@ fn no_lines(s string) string {
 fn test_struct_readline() {
 	// mut rl := Readline{}
 	// eprintln('rl: $rl')
-	// line := rl.read_line('Please, enter your name: ') or { panic(err.msg) }
+	// line := rl.read_line('Please, enter your name: ') or { panic(err) }
 	// eprintln('line: $line')
 	mut methods := []string{}
 	$for method in Readline.methods {
diff --git a/vlib/sqlite/sqlite_test.v b/vlib/sqlite/sqlite_test.v
index 47068ac7e8..ebcd3aa10a 100644
--- a/vlib/sqlite/sqlite_test.v
+++ b/vlib/sqlite/sqlite_test.v
@@ -5,7 +5,7 @@ fn test_sqlite() {
 		return
 	}
 	mut db := sqlite.connect(':memory:') or {
-		panic(err.msg)
+		panic(err)
 	}
 	assert db.is_open
 	db.exec('drop table if exists users')
@@ -23,11 +23,11 @@ fn test_sqlite() {
 	code = db.exec_none('vacuum')
 	assert code == 101
 	user := db.exec_one('select * from users where id = 3') or {
-		panic(err.msg)
+		panic(err)
 	}
 	assert user.vals.len == 2
 	db.close() or {
-		panic(err.msg)
+		panic(err)
 	}
 	assert !db.is_open
 }
diff --git a/vlib/term/ui/termios_nix.c.v b/vlib/term/ui/termios_nix.c.v
index 13050ccdc3..b2c0357e00 100644
--- a/vlib/term/ui/termios_nix.c.v
+++ b/vlib/term/ui/termios_nix.c.v
@@ -125,7 +125,7 @@ fn (mut ctx Context) termios_setup() ? {
 	os.signal(C.SIGCONT, fn () {
 		mut c := ctx_ptr
 		if c != 0 {
-			c.termios_setup() or { panic(err.msg) }
+			c.termios_setup() or { panic(err) }
 			c.window_height, c.window_width = get_terminal_size()
 			mut event := &Event{
 				typ: .resized
diff --git a/vlib/v/builder/builder.v b/vlib/v/builder/builder.v
index 813fcdb4f6..99a213838e 100644
--- a/vlib/v/builder/builder.v
+++ b/vlib/v/builder/builder.v
@@ -205,7 +205,7 @@ pub fn (b Builder) v_files_from_dir(dir string) []string {
 	} else if !os.is_dir(dir) {
 		verror("$dir isn't a directory!")
 	}
-	mut files := os.ls(dir) or { panic(err.msg) }
+	mut files := os.ls(dir) or { panic(err) }
 	if b.pref.is_verbose {
 		println('v_files_from_dir ("$dir")')
 	}
diff --git a/vlib/v/builder/c.v b/vlib/v/builder/c.v
index c5c5598a30..b0da21f188 100644
--- a/vlib/v/builder/c.v
+++ b/vlib/v/builder/c.v
@@ -42,8 +42,8 @@ pub fn (mut b Builder) build_c(v_files []string, out_file string) {
 	b.pref.out_name_c = os.real_path(out_file)
 	b.info('build_c($out_file)')
 	output2 := b.gen_c(v_files)
-	mut f := os.create(out_file) or { panic(err.msg) }
-	f.writeln(output2) or { panic(err.msg) }
+	mut f := os.create(out_file) or { panic(err) }
+	f.writeln(output2) or { panic(err) }
 	f.close()
 	if b.pref.is_stats {
 		println('generated C source code size: ${util.bold((output2.count('\n') + 1).str())} lines, ${util.bold(output2.len.str())} bytes')
@@ -86,9 +86,9 @@ pub fn (mut b Builder) compile_c() {
 		bundle_name := b.pref.out_name.split('/').last()
 		bundle_id := if b.pref.bundle_id != '' { b.pref.bundle_id } else { 'app.vlang.$bundle_name' }
 		display_name := if b.pref.display_name != '' { b.pref.display_name } else { bundle_name }
-		os.mkdir('${display_name}.app') or { panic(err.msg) }
+		os.mkdir('${display_name}.app') or { panic(err) }
 		os.write_file('${display_name}.app/Info.plist', make_ios_plist(display_name, bundle_id,
-			bundle_name, 1)) or { panic(err.msg) }
+			bundle_name, 1)) or { panic(err) }
 	}
 	b.cc()
 }
diff --git a/vlib/v/builder/cc.v b/vlib/v/builder/cc.v
index a4d186906d..cde45d1a00 100644
--- a/vlib/v/builder/cc.v
+++ b/vlib/v/builder/cc.v
@@ -90,7 +90,7 @@ fn (mut v Builder) post_process_c_compiler_output(res os.Result) {
 				if v.pref.is_verbose {
 					eprintln('>> remove tmp file: $tmpfile')
 				}
-				os.rm(tmpfile) or { panic(err.msg) }
+				os.rm(tmpfile) or { panic(err) }
 			}
 		}
 		return
@@ -418,7 +418,7 @@ fn (mut v Builder) setup_output_name() {
 			println('Building $v.pref.path to $v.pref.out_name ...')
 		}
 		v.pref.cache_manager.save('.description.txt', v.pref.path, '${v.pref.path:-30} @ $v.pref.cache_manager.vopts\n') or {
-			panic(err.msg)
+			panic(err)
 		}
 		// println('v.table.imports:')
 		// println(v.table.imports)
@@ -469,7 +469,7 @@ fn (mut v Builder) vjs_cc() bool {
 			}
 		}
 		// v.out_name_c may be on a different partition than v.out_name
-		os.mv_by_cp(v.out_name_c, v.pref.out_name) or { panic(err.msg) }
+		os.mv_by_cp(v.out_name_c, v.pref.out_name) or { panic(err) }
 		return true
 	}
 	return false
@@ -481,7 +481,7 @@ fn (mut v Builder) dump_c_options(all_args []string) {
 		if v.pref.dump_c_flags == '-' {
 			print(non_empty_args)
 		} else {
-			os.write_file(v.pref.dump_c_flags, non_empty_args) or { panic(err.msg) }
+			os.write_file(v.pref.dump_c_flags, non_empty_args) or { panic(err) }
 		}
 	}
 }
@@ -759,7 +759,7 @@ fn (mut b Builder) cc_linux_cross() {
 	b.setup_output_name()
 	parent_dir := os.vmodules_dir()
 	if !os.exists(parent_dir) {
-		os.mkdir(parent_dir) or { panic(err.msg) }
+		os.mkdir(parent_dir) or { panic(err) }
 	}
 	sysroot := os.join_path(os.vmodules_dir(), 'linuxroot')
 	if !os.is_dir(sysroot) {
@@ -963,7 +963,7 @@ fn (mut v Builder) build_thirdparty_obj_file(path string, moduleflags []cflag.CF
 		// for example thirdparty\tcc\lib\openlibm.o
 		// the best we can do for them is just copy them,
 		// and hope that they work with any compiler...
-		os.cp(obj_path, opath) or { panic(err.msg) }
+		os.cp(obj_path, opath) or { panic(err) }
 		return
 	}
 	println('$obj_path not found, building it in $opath ...')
@@ -994,7 +994,7 @@ fn (mut v Builder) build_thirdparty_obj_file(path string, moduleflags []cflag.CF
 		return
 	}
 	v.pref.cache_manager.save('.description.txt', obj_path, '${obj_path:-30} @ $cmd\n') or {
-		panic(err.msg)
+		panic(err)
 	}
 	println(res.output)
 }
diff --git a/vlib/v/builder/compile.v b/vlib/v/builder/compile.v
index 82029cfdee..dd33228f0a 100644
--- a/vlib/v/builder/compile.v
+++ b/vlib/v/builder/compile.v
@@ -93,12 +93,12 @@ fn (mut b Builder) run_compiled_executable_and_exit() {
 	}
 	if b.pref.os == .ios {
 		device := '"iPhone SE (2nd generation)"'
-		os.exec('xcrun simctl boot $device') or { panic(err.msg) }
+		os.exec('xcrun simctl boot $device') or { panic(err) }
 		bundle_name := b.pref.out_name.split('/').last()
 		display_name := if b.pref.display_name != '' { b.pref.display_name } else { bundle_name }
-		os.exec('xcrun simctl install $device ${display_name}.app') or { panic(err.msg) }
+		os.exec('xcrun simctl install $device ${display_name}.app') or { panic(err) }
 		bundle_id := if b.pref.bundle_id != '' { b.pref.bundle_id } else { 'app.vlang.$bundle_name' }
-		os.exec('xcrun simctl launch $device $bundle_id') or { panic(err.msg) }
+		os.exec('xcrun simctl launch $device $bundle_id') or { panic(err) }
 	} else {
 		exefile := os.real_path(b.pref.out_name)
 		mut cmd := '"$exefile"'
@@ -133,7 +133,7 @@ fn (mut v Builder) cleanup_run_executable_after_exit(exefile string) {
 	}
 	if os.is_file(exefile) {
 		v.pref.vrun_elog('remove run executable: $exefile')
-		os.rm(exefile) or { panic(err.msg) }
+		os.rm(exefile) or { panic(err) }
 	}
 }
 
diff --git a/vlib/v/builder/js.v b/vlib/v/builder/js.v
index a6ae08a749..0a2b149731 100644
--- a/vlib/v/builder/js.v
+++ b/vlib/v/builder/js.v
@@ -34,8 +34,8 @@ pub fn (mut b Builder) build_js(v_files []string, out_file string) {
 	b.out_name_js = out_file
 	b.info('build_js($out_file)')
 	output := b.gen_js(v_files)
-	mut f := os.create(out_file) or { panic(err.msg) }
-	f.writeln(output) or { panic(err.msg) }
+	mut f := os.create(out_file) or { panic(err) }
+	f.writeln(output) or { panic(err) }
 	f.close()
 }
 
diff --git a/vlib/v/builder/msvc.v b/vlib/v/builder/msvc.v
index b4ef5acf5d..4a259441fc 100644
--- a/vlib/v/builder/msvc.v
+++ b/vlib/v/builder/msvc.v
@@ -329,7 +329,7 @@ pub fn (mut v Builder) cc_msvc() {
 	// println(res)
 	// println('C OUTPUT:')
 	// Always remove the object file - it is completely unnecessary
-	os.rm(out_name_obj) or { panic(err.msg) }
+	os.rm(out_name_obj) or { panic(err) }
 }
 
 fn (mut v Builder) build_thirdparty_obj_file_with_msvc(path string, moduleflags []cflag.CFlag) {
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index ae749ce22f..490c239962 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -3656,7 +3656,7 @@ pub fn (mut c Checker) expr(node ast.Expr) table.Type {
 			return node.typ.to_ptr()
 		}
 		ast.Assoc {
-			v := node.scope.find_var(node.var_name) or { panic(err.msg) }
+			v := node.scope.find_var(node.var_name) or { panic(err) }
 			for i, _ in node.fields {
 				c.expr(node.exprs[i])
 			}
diff --git a/vlib/v/compiler_errors_test.v b/vlib/v/compiler_errors_test.v
index 31ca3c70a2..071719085c 100644
--- a/vlib/v/compiler_errors_test.v
+++ b/vlib/v/compiler_errors_test.v
@@ -239,14 +239,14 @@ fn (mut task TaskDescription) execute() {
 	}
 	program := task.path
 	cli_cmd := '$task.vexe $task.voptions $program'
-	res := os.exec(cli_cmd) or { panic(err.msg) }
+	res := os.exec(cli_cmd) or { panic(err) }
 	expected_out_path := program.replace('.vv', '') + task.result_extension
 	task.expected_out_path = expected_out_path
 	task.cli_cmd = cli_cmd
 	if should_autofix && !os.exists(expected_out_path) {
-		os.write_file(expected_out_path, '') or { panic(err.msg) }
+		os.write_file(expected_out_path, '') or { panic(err) }
 	}
-	mut expected := os.read_file(expected_out_path) or { panic(err.msg) }
+	mut expected := os.read_file(expected_out_path) or { panic(err) }
 	task.expected = clean_line_endings(expected)
 	task.found___ = clean_line_endings(res.output)
 	$if windows {
@@ -257,7 +257,7 @@ fn (mut task TaskDescription) execute() {
 	if task.expected != task.found___ {
 		task.is_error = true
 		if should_autofix {
-			os.write_file(expected_out_path, res.output) or { panic(err.msg) }
+			os.write_file(expected_out_path, res.output) or { panic(err) }
 		}
 	}
 }
@@ -279,7 +279,7 @@ fn diff_content(s1 string, s2 string) {
 }
 
 fn get_tests_in_dir(dir string, is_module bool) []string {
-	files := os.ls(dir) or { panic(err.msg) }
+	files := os.ls(dir) or { panic(err) }
 	mut tests := files.clone()
 	if !is_module {
 		tests = files.filter(it.ends_with('.vv'))
diff --git a/vlib/v/fmt/fmt_keep_test.v b/vlib/v/fmt/fmt_keep_test.v
index 2d5330d290..3b130ccc73 100644
--- a/vlib/v/fmt/fmt_keep_test.v
+++ b/vlib/v/fmt/fmt_keep_test.v
@@ -67,7 +67,7 @@ fn test_fmt() {
 				continue
 			}
 			vfmt_result_file := os.join_path(tmpfolder, 'vfmt_run_over_$ifilename')
-			os.write_file(vfmt_result_file, result_ocontent) or { panic(err.msg) }
+			os.write_file(vfmt_result_file, result_ocontent) or { panic(err) }
 			eprintln(util.color_compare_files(diff_cmd, opath, vfmt_result_file))
 			continue
 		}
diff --git a/vlib/v/fmt/fmt_test.v b/vlib/v/fmt/fmt_test.v
index 74ca947d10..a4a620c4e2 100644
--- a/vlib/v/fmt/fmt_test.v
+++ b/vlib/v/fmt/fmt_test.v
@@ -59,7 +59,7 @@ fn test_fmt() {
 				continue
 			}
 			vfmt_result_file := os.join_path(tmpfolder, 'vfmt_run_over_$ifilename')
-			os.write_file(vfmt_result_file, result_ocontent) or { panic(err.msg) }
+			os.write_file(vfmt_result_file, result_ocontent) or { panic(err) }
 			eprintln(util.color_compare_files(diff_cmd, opath, vfmt_result_file))
 			continue
 		}
diff --git a/vlib/v/fmt/fmt_vlib_test.v b/vlib/v/fmt/fmt_vlib_test.v
index 7936c50adf..8e004db10c 100644
--- a/vlib/v/fmt/fmt_vlib_test.v
+++ b/vlib/v/fmt/fmt_vlib_test.v
@@ -57,7 +57,7 @@ fn test_vlib_fmt() {
 				continue
 			}
 			vfmt_result_file := os.join_path(tmpfolder, 'vfmt_run_over_$ifilename')
-			os.write_file(vfmt_result_file, result_ocontent) or { panic(err.msg) }
+			os.write_file(vfmt_result_file, result_ocontent) or { panic(err) }
 			eprintln(util.color_compare_files(diff_cmd, opath, vfmt_result_file))
 			continue
 		}
diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index f3a2a967f6..f0b121635b 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -5590,7 +5590,7 @@ fn (mut g Gen) or_block(var_name string, or_block ast.OrExpr, return_type table.
 		}
 	} else if or_block.kind == .propagate {
 		if g.file.mod.name == 'main' && (isnil(g.fn_decl) || g.fn_decl.name == 'main.main') {
-			// In main(), an `opt()?` call is sugar for `opt() or { panic(err.msg) }`
+			// In main(), an `opt()?` call is sugar for `opt() or { panic(err) }`
 			if g.pref.is_debug {
 				paline, pafile, pamod, pafn := g.panic_debug_info(or_block.pos)
 				g.writeln('panic_debug($paline, tos3("$pafile"), tos3("$pamod"), tos3("$pafn"), ${cvar_name}.err.msg );')
diff --git a/vlib/v/gen/c/cgen_test.v b/vlib/v/gen/c/cgen_test.v
index b96a110ce8..1aa5b5de50 100644
--- a/vlib/v/gen/c/cgen_test.v
+++ b/vlib/v/gen/c/cgen_test.v
@@ -18,7 +18,7 @@ fn test_c_files() {
 	vroot := os.dir(vexe)
 	for i in 1 .. (nr_tests + 1) {
 		path := '$vroot/vlib/v/gen/tests/${i}.vv'
-		ctext := os.read_file('$vroot/vlib/v/gen/tests/${i}.c') or { panic(err.msg) }
+		ctext := os.read_file('$vroot/vlib/v/gen/tests/${i}.c') or { panic(err) }
 		mut b := builder.new_builder(&pref.Preferences{})
 		b.module_search_paths = ['$vroot/vlib/v/gen/tests/']
 		mut res := b.gen_c([path]).after('#endbuiltin')
diff --git a/vlib/v/gen/js/jsgen_test.v b/vlib/v/gen/js/jsgen_test.v
index d1d8ee561a..2115b8fb68 100644
--- a/vlib/v/gen/js/jsgen_test.v
+++ b/vlib/v/gen/js/jsgen_test.v
@@ -15,7 +15,7 @@ const there_is_node_available = is_nodejs_working()
 fn test_example_compilation() {
 	vexe := os.getenv('VEXE')
 	os.chdir(os.dir(vexe))
-	os.mkdir_all(output_dir) or { panic(err.msg) }
+	os.mkdir_all(output_dir) or { panic(err) }
 	files := find_test_files()
 	for file in files {
 		path := os.join_path(test_dir, file)
@@ -40,7 +40,7 @@ fn test_example_compilation() {
 }
 
 fn find_test_files() []string {
-	files := os.ls(test_dir) or { panic(err.msg) }
+	files := os.ls(test_dir) or { panic(err) }
 	// The life example never exits, so tests would hang with it, skip
 	mut tests := files.filter(it.ends_with('.v')).filter(it != 'life.v')
 	tests.sort()
diff --git a/vlib/v/gen/x64/elf.v b/vlib/v/gen/x64/elf.v
index 4cf598b63b..5ffbc73d25 100644
--- a/vlib/v/gen/x64/elf.v
+++ b/vlib/v/gen/x64/elf.v
@@ -99,7 +99,7 @@ pub fn (mut g Gen) generate_elf_footer() {
 	// -5 is for "e8 00 00 00 00"
 	g.write32_at(g.code_start_pos + 1, int(g.main_fn_addr - g.code_start_pos) - 5)
 	// Create the binary
-	mut f := os.create(g.out_name) or { panic(err.msg) }
+	mut f := os.create(g.out_name) or { panic(err) }
 	os.chmod(g.out_name, 0o775) // make it an executable
 	unsafe { f.write_bytes(g.buf.data, g.buf.len) }
 	f.close()
diff --git a/vlib/v/gen/x64/tests/x64_test.v b/vlib/v/gen/x64/tests/x64_test.v
index 296c90f29b..c1905481f8 100644
--- a/vlib/v/gen/x64/tests/x64_test.v
+++ b/vlib/v/gen/x64/tests/x64_test.v
@@ -15,10 +15,10 @@ fn test_x64() {
 	vexe := os.getenv('VEXE')
 	vroot := os.dir(vexe)
 	dir := os.join_path(vroot, 'vlib/v/gen/x64/tests')
-	files := os.ls(dir) or { panic(err.msg) }
+	files := os.ls(dir) or { panic(err) }
 	//
 	wrkdir := os.join_path(os.temp_dir(), 'vtests', 'x64')
-	os.mkdir_all(wrkdir) or { panic(err.msg) }
+	os.mkdir_all(wrkdir) or { panic(err) }
 	os.chdir(wrkdir)
 	tests := files.filter(it.ends_with('.vv'))
 	if tests.len == 0 {
@@ -46,7 +46,7 @@ fn test_x64() {
 			eprintln(res.output)
 			continue
 		}
-		mut expected := os.read_file('$dir/${test}.out') or { panic(err.msg) }
+		mut expected := os.read_file('$dir/${test}.out') or { panic(err) }
 		expected = expected.trim_right('\r\n').replace('\r\n', '\n')
 		mut found := res.output.trim_right('\r\n').replace('\r\n', '\n')
 		found = found.trim_space()
diff --git a/vlib/v/live/live_test.v b/vlib/v/live/live_test.v
index 85ef59c47c..816d44ee0a 100644
--- a/vlib/v/live/live_test.v
+++ b/vlib/v/live/live_test.v
@@ -44,7 +44,7 @@ const (
 )
 
 fn get_source_template() string {
-	src := os.read_file(os.join_path(os.dir(@FILE), 'live_test_template.vv')) or { panic(err.msg) }
+	src := os.read_file(os.join_path(os.dir(@FILE), 'live_test_template.vv')) or { panic(err) }
 	return src.replace('#OUTPUT_FILE#', output_file)
 }
 
@@ -60,8 +60,8 @@ fn atomic_write_source(source string) {
 	// NB: here wrtiting is done in 2 steps, since os.write_file can take some time,
 	// during which the file will be modified, but it will still be not completely written.
 	// The os.mv after that, guarantees that the reloader will see a complete valid V program.
-	os.write_file(tmp_file, source) or { panic(err.msg) }
-	os.mv(tmp_file, source_file) or { panic(err.msg) }
+	os.write_file(tmp_file, source) or { panic(err) }
+	os.mv(tmp_file, source_file) or { panic(err) }
 }
 
 //
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index a3fe12025e..72e0218f47 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -152,7 +152,7 @@ pub fn parse_file(path string, table &table.Table, comments_mode scanner.Comment
 	// for handling them, and should be removed when we do (the general solution is also needed for vfmt)
 	// println('parse_file("$path")')
 	// text := os.read_file(path) or {
-	// panic(err.msg)
+	// panic(err)
 	// }
 	mut p := Parser{
 		scanner: scanner.new_scanner_file(path, comments_mode, pref)
diff --git a/vlib/v/pref/pref.v b/vlib/v/pref/pref.v
index a2558a0b19..86513a5e54 100644
--- a/vlib/v/pref/pref.v
+++ b/vlib/v/pref/pref.v
@@ -488,7 +488,7 @@ pub fn parse_args(known_external_commands []string, args []string) (&Preferences
 				os.rm(tmp_exe_file_path) or { }
 			}
 			res.vrun_elog('remove tmp v file: $tmp_v_file_path')
-			os.rm(tmp_v_file_path) or { panic(err.msg) }
+			os.rm(tmp_v_file_path) or { panic(err) }
 			exit(tmp_result)
 		}
 		must_exist(res.path)
diff --git a/vlib/v/tests/anon_fn_returning_question_test.v b/vlib/v/tests/anon_fn_returning_question_test.v
index 5e5f443e09..36cd2732d8 100644
--- a/vlib/v/tests/anon_fn_returning_question_test.v
+++ b/vlib/v/tests/anon_fn_returning_question_test.v
@@ -1,7 +1,7 @@
 type FnCb = fn (a string, b int) ?
 
 fn test_calling_an_anon_function_returning_question() {
-	create_and_call_anon_function() or { panic(err.msg) }
+	create_and_call_anon_function() or { panic(err) }
 }
 
 fn create_and_call_anon_function() ? {
diff --git a/vlib/v/tests/inout/compiler_test.v b/vlib/v/tests/inout/compiler_test.v
index 80c4bf08c1..6b03a72b07 100644
--- a/vlib/v/tests/inout/compiler_test.v
+++ b/vlib/v/tests/inout/compiler_test.v
@@ -16,7 +16,7 @@ fn test_all() {
 	os.chdir(vroot)
 	diff_cmd := util.find_working_diff_command() or { '' }
 	dir := 'vlib/v/tests/inout'
-	files := os.ls(dir) or { panic(err.msg) }
+	files := os.ls(dir) or { panic(err) }
 	tests := files.filter(it.ends_with('.vv'))
 	if tests.len == 0 {
 		println('no compiler tests found')
@@ -28,13 +28,13 @@ fn test_all() {
 	for path in paths {
 		print(path + ' ')
 		program := path
-		compilation := os.exec('$vexe -o test -cflags "-w" -cg $program') or { panic(err.msg) }
+		compilation := os.exec('$vexe -o test -cflags "-w" -cg $program') or { panic(err) }
 		if compilation.exit_code != 0 {
 			panic('compilation failed: $compilation.output')
 		}
 		res := os.exec('./test') or {
 			println('nope')
-			panic(err.msg)
+			panic(err)
 		}
 		$if windows {
 			os.rm('./test.exe') or { }
@@ -49,7 +49,7 @@ fn test_all() {
 		// println(res.output)
 		// println('============')
 		mut found := res.output.trim_right('\r\n').replace('\r\n', '\n')
-		mut expected := os.read_file(program.replace('.vv', '') + '.out') or { panic(err.msg) }
+		mut expected := os.read_file(program.replace('.vv', '') + '.out') or { panic(err) }
 		expected = expected.trim_right('\r\n').replace('\r\n', '\n')
 		if expected.contains('================ V panic ================') {
 			// panic include backtraces and absolute file paths, so can't do char by char comparison
diff --git a/vlib/v/tests/multiple_paths_in_vmodules/vmodules_overrides_test.v b/vlib/v/tests/multiple_paths_in_vmodules/vmodules_overrides_test.v
index e184ee86b4..0212027941 100644
--- a/vlib/v/tests/multiple_paths_in_vmodules/vmodules_overrides_test.v
+++ b/vlib/v/tests/multiple_paths_in_vmodules/vmodules_overrides_test.v
@@ -18,7 +18,7 @@ fn test_vexe_is_set() {
 fn test_compiling_without_vmodules_fails() {
 	os.chdir(vroot)
 	os.setenv('VMODULES', '', true)
-	res := os.exec('"$vexe" run "$mainvv"') or { panic(err.msg) }
+	res := os.exec('"$vexe" run "$mainvv"') or { panic(err) }
 	assert res.exit_code == 1
 	assert res.output.trim_space().contains('builder error: cannot import module "yyy" (not found)')
 }
@@ -27,7 +27,7 @@ fn test_compiling_with_vmodules_works() {
 	os.chdir(vroot)
 	vmpaths := ['path1', 'path2', 'path3'].map(os.join_path(basepath, it))
 	os.setenv('VMODULES', vmpaths.join(os.path_delimiter), true)
-	res := os.exec('"$vexe" run "$mainvv"') or { panic(err.msg) }
+	res := os.exec('"$vexe" run "$mainvv"') or { panic(err) }
 	assert res.exit_code == 0
 	assert res.output.trim_space() == "['x', 'y', 'z']"
 }
diff --git a/vlib/v/tests/option_test.v b/vlib/v/tests/option_test.v
index 968b6a99ff..d48237060a 100644
--- a/vlib/v/tests/option_test.v
+++ b/vlib/v/tests/option_test.v
@@ -84,7 +84,7 @@ fn for_opt_default() ?string {
 
 fn test_opt_default() {
 	a := for_opt_default() or {
-		// panic(err.msg)
+		// panic(err)
 		'default'
 	}
 	assert a == 'default'
@@ -258,7 +258,7 @@ fn multi_return_opt(err bool) (string, string) {
 
 fn test_multi_return_opt() {
 	a, b := multi_return_opt(false) or {
-		panic(err.msg)
+		panic(err)
 	}
 	assert a == 'hello' && b == 'v'
 	_, _ := multi_return_opt(true) or {
diff --git a/vlib/v/tests/orm_sub_struct_test.v b/vlib/v/tests/orm_sub_struct_test.v
index 8eba69f5b8..938fd888ee 100644
--- a/vlib/v/tests/orm_sub_struct_test.v
+++ b/vlib/v/tests/orm_sub_struct_test.v
@@ -11,7 +11,7 @@ struct SubStruct {
 }
 
 fn test_orm_sub_structs() {
-	db := sqlite.connect(':memory:') or { panic(err.msg) }
+	db := sqlite.connect(':memory:') or { panic(err) }
 	db.exec('create table Upper (id integer primary key, sub int default 0)')
 	db.exec('create table SubStruct (id integer primary key, name string default "")')
 
diff --git a/vlib/v/tests/repl/repl_test.v b/vlib/v/tests/repl/repl_test.v
index 347f7d3379..33312a19cc 100644
--- a/vlib/v/tests/repl/repl_test.v
+++ b/vlib/v/tests/repl/repl_test.v
@@ -12,11 +12,11 @@ fn test_the_v_compiler_can_be_invoked() {
 	println('vexecutable: $vexec')
 	assert vexec != ''
 	vcmd := '"$vexec" -version'
-	r := os.exec(vcmd) or { panic(err.msg) }
+	r := os.exec(vcmd) or { panic(err) }
 	// println('"$vcmd" exit_code: $r.exit_code | output: $r.output')
 	assert r.exit_code == 0
 	vcmd_error := '"$vexec" nonexisting.v'
-	r_error := os.exec(vcmd_error) or { panic(err.msg) }
+	r_error := os.exec(vcmd_error) or { panic(err) }
 	// println('"$vcmd_error" exit_code: $r_error.exit_code | output: $r_error.output')
 	assert r_error.exit_code == 1
 	actual_error := r_error.output.trim_space()
@@ -36,7 +36,7 @@ fn test_all_v_repl_files() {
 	}
 	// warmup, and ensure that the vrepl is compiled in single threaded mode if it does not exist
 	runner.run_repl_file(os.cache_dir(), session.options.vexec, 'vlib/v/tests/repl/nothing.repl') or {
-		panic(err.msg)
+		panic(err)
 	}
 	session.bmark.set_total_expected_steps(session.options.files.len)
 	mut pool_repl := pool.new_pool_processor(
@@ -64,23 +64,23 @@ fn worker_repl(mut p pool.PoolProcessor, idx int, thread_id int) voidptr {
 	tls_bench.cstep = idx
 	tfolder := os.join_path(cdir, 'vrepl_tests_$idx')
 	if os.is_dir(tfolder) {
-		os.rmdir_all(tfolder) or { panic(err.msg) }
+		os.rmdir_all(tfolder) or { panic(err) }
 	}
-	os.mkdir(tfolder) or { panic(err.msg) }
+	os.mkdir(tfolder) or { panic(err) }
 	file := p.get_item<string>(idx)
 	session.bmark.step()
 	tls_bench.step()
 	fres := runner.run_repl_file(tfolder, session.options.vexec, file) or {
 		session.bmark.fail()
 		tls_bench.fail()
-		os.rmdir_all(tfolder) or { panic(err.msg) }
+		os.rmdir_all(tfolder) or { panic(err) }
 		eprintln(tls_bench.step_message_fail(err.msg))
 		assert false
 		return pool.no_result
 	}
 	session.bmark.ok()
 	tls_bench.ok()
-	os.rmdir_all(tfolder) or { panic(err.msg) }
+	os.rmdir_all(tfolder) or { panic(err) }
 	println(tls_bench.step_message_ok(fres))
 	assert true
 	return pool.no_result
diff --git a/vlib/v/tests/repl/runner/runner.v b/vlib/v/tests/repl/runner/runner.v
index 8e6b4984a1..4ec542475e 100644
--- a/vlib/v/tests/repl/runner/runner.v
+++ b/vlib/v/tests/repl/runner/runner.v
@@ -47,22 +47,22 @@ pub fn run_repl_file(wd string, vexec string, file string) ?string {
 	output := content.all_after('===output===\n').trim_right('\n\r')
 	fname := os.file_name(file)
 	input_temporary_filename := os.real_path(os.join_path(wd, 'input_temporary_filename.txt'))
-	os.write_file(input_temporary_filename, input) or { panic(err.msg) }
-	os.write_file(os.real_path(os.join_path(wd, 'original.txt')), fcontent) or { panic(err.msg) }
+	os.write_file(input_temporary_filename, input) or { panic(err) }
+	os.write_file(os.real_path(os.join_path(wd, 'original.txt')), fcontent) or { panic(err) }
 	rcmd := '"$vexec" repl -replfolder "$wd" -replprefix "${fname}." < $input_temporary_filename'
 	r := os.exec(rcmd) or {
-		os.rm(input_temporary_filename) or { panic(err.msg) }
+		os.rm(input_temporary_filename) or { panic(err) }
 		return error('Could not execute: $rcmd')
 	}
-	os.rm(input_temporary_filename) or { panic(err.msg) }
+	os.rm(input_temporary_filename) or { panic(err) }
 	result := r.output.replace('\r', '').replace('>>> ', '').replace('>>>', '').replace('... ',
 		'').replace(wd + os.path_separator, '').replace(vexec_folder, '').replace('\\',
 		'/').trim_right('\n\r')
 	if result != output {
 		file_result := '${file}.result.txt'
 		file_expected := '${file}.expected.txt'
-		os.write_file(file_result, result) or { panic(err.msg) }
-		os.write_file(file_expected, output) or { panic(err.msg) }
+		os.write_file(file_result, result) or { panic(err) }
+		os.write_file(file_expected, output) or { panic(err) }
 		diff := diff_files(file_expected, file_result)
 		return error('Difference found in REPL file: $file
 ====> Expected :
@@ -91,7 +91,7 @@ pub fn run_prod_file(wd string, vexec string, file string) ?string {
 	result := r.output.replace('\r', '')
 	if result != expected_content {
 		file_result := '${file}.result.txt'
-		os.write_file(file_result, result) or { panic(err.msg) }
+		os.write_file(file_result, result) or { panic(err) }
 		diff := diff_files(file_result, file_expected)
 		return error('Difference found in test: $file
 ====> Got      :
diff --git a/vlib/v/tests/run_v_code_from_stdin_test.v b/vlib/v/tests/run_v_code_from_stdin_test.v
index 327369c51c..fde6f33444 100644
--- a/vlib/v/tests/run_v_code_from_stdin_test.v
+++ b/vlib/v/tests/run_v_code_from_stdin_test.v
@@ -19,10 +19,10 @@ fn pipe_to_v_run() ? {
 	// eprintln('>> cmd: $cmd | res: $res')
 	assert res.exit_code == 0
 	assert res.output.replace('\r', '').trim_space().split('\n') == ['4', 'hello']
-	os.rm(tmp_v_file) or { panic(err.msg) }
+	os.rm(tmp_v_file) or { panic(err) }
 	assert !os.exists(tmp_v_file)
 }
 
 fn test_pipe_to_v_run() {
-	pipe_to_v_run() or { panic(err.msg) }
+	pipe_to_v_run() or { panic(err) }
 }
diff --git a/vlib/v/tests/valgrind/valgrind_test.v b/vlib/v/tests/valgrind/valgrind_test.v
index b4e0790c54..c3110e93c1 100644
--- a/vlib/v/tests/valgrind/valgrind_test.v
+++ b/vlib/v/tests/valgrind/valgrind_test.v
@@ -50,10 +50,10 @@ fn test_all() {
 	vroot := os.dir(vexe)
 	valgrind_test_path := 'vlib/v/tests/valgrind'
 	dir := os.join_path(vroot, valgrind_test_path)
-	files := os.ls(dir) or { panic(err.msg) }
+	files := os.ls(dir) or { panic(err) }
 	//
 	wrkdir := os.join_path(os.temp_dir(), 'vtests', 'valgrind')
-	os.mkdir_all(wrkdir) or { panic(err.msg) }
+	os.mkdir_all(wrkdir) or { panic(err) }
 	os.chdir(wrkdir)
 	//
 	only_ordinary_v_files := files.filter(it.ends_with('.v') && !it.ends_with('_test.v'))
diff --git a/vlib/v/tests/vargs_empty_param_test.v b/vlib/v/tests/vargs_empty_param_test.v
index 03cbcbf6a6..c89eceeb09 100644
--- a/vlib/v/tests/vargs_empty_param_test.v
+++ b/vlib/v/tests/vargs_empty_param_test.v
@@ -14,7 +14,7 @@ fn new(config Config, shard_count ...int) ?&Client {
 fn test_can_compile_an_empty_var_arg() {
 	x := new(Config{
 		token: 'xyz'
-	}) or { panic(err.msg) }
+	}) or { panic(err) }
 	assert x.x == 1
 	assert x.y == 2
 }
diff --git a/vlib/v/tests/vmod_parser_test.v b/vlib/v/tests/vmod_parser_test.v
index 141caf0ef7..e8db9d9bae 100644
--- a/vlib/v/tests/vmod_parser_test.v
+++ b/vlib/v/tests/vmod_parser_test.v
@@ -3,7 +3,7 @@ import os
 
 fn test_from_file() {
 	os.chdir(os.dir(os.getenv('VEXE')))
-	data := vmod.from_file('./v.mod') or { panic(err.msg) }
+	data := vmod.from_file('./v.mod') or { panic(err) }
 	assert data.name == 'V'
 	assert data.description == 'The V programming language.'
 	//assert data.version == '0.2.1'
diff --git a/vlib/v/util/diff.v b/vlib/v/util/diff.v
index 1c46a365db..90fe7c8c25 100644
--- a/vlib/v/util/diff.v
+++ b/vlib/v/util/diff.v
@@ -64,10 +64,10 @@ pub fn color_compare_strings(diff_cmd string, expected string, found string) str
 	ctime := time.sys_mono_now()
 	e_file := os.join_path(cdir, '${ctime}.expected.txt')
 	f_file := os.join_path(cdir, '${ctime}.found.txt')
-	os.write_file(e_file, expected) or { panic(err.msg) }
-	os.write_file(f_file, found) or { panic(err.msg) }
+	os.write_file(e_file, expected) or { panic(err) }
+	os.write_file(f_file, found) or { panic(err) }
 	res := color_compare_files(diff_cmd, e_file, f_file)
-	os.rm(e_file) or { panic(err.msg) }
-	os.rm(f_file) or { panic(err.msg) }
+	os.rm(e_file) or { panic(err) }
+	os.rm(f_file) or { panic(err) }
 	return res
 }
diff --git a/vlib/v/util/util.v b/vlib/v/util/util.v
index 1a8bc53ed8..28d1c11a17 100644
--- a/vlib/v/util/util.v
+++ b/vlib/v/util/util.v
@@ -214,7 +214,7 @@ pub fn launch_tool(is_verbose bool, tool_name string, args []string) {
 	if should_compile {
 		emodules := util.external_module_dependencies_for_tool[tool_name]
 		for emodule in emodules {
-			check_module_is_installed(emodule, is_verbose) or { panic(err.msg) }
+			check_module_is_installed(emodule, is_verbose) or { panic(err) }
 		}
 		mut compilation_command := '"$vexe" '
 		if tool_name in ['vself', 'vup', 'vdoctor', 'vsymlink'] {
@@ -229,7 +229,7 @@ pub fn launch_tool(is_verbose bool, tool_name string, args []string) {
 		if is_verbose {
 			println('Compiling $tool_name with: "$compilation_command"')
 		}
-		tool_compilation := os.exec(compilation_command) or { panic(err.msg) }
+		tool_compilation := os.exec(compilation_command) or { panic(err) }
 		if tool_compilation.exit_code != 0 {
 			eprintln('cannot compile `$tool_source`: \n$tool_compilation.output')
 			exit(1)
@@ -462,7 +462,7 @@ pub fn ensure_modules_for_all_tools_are_installed(is_verbose bool) {
 			eprintln('Installing modules for tool: $tool_name ...')
 		}
 		for emodule in tool_modules {
-			check_module_is_installed(emodule, is_verbose) or { panic(err.msg) }
+			check_module_is_installed(emodule, is_verbose) or { panic(err) }
 		}
 	}
 }
@@ -535,7 +535,7 @@ pub fn get_vtmp_folder() string {
 	}
 	vtmp = os.join_path(os.temp_dir(), 'v')
 	if !os.exists(vtmp) || !os.is_dir(vtmp) {
-		os.mkdir_all(vtmp) or { panic(err.msg) }
+		os.mkdir_all(vtmp) or { panic(err) }
 	}
 	os.setenv('VTMP', vtmp, true)
 	return vtmp
diff --git a/vlib/v/vcache/vcache.v b/vlib/v/vcache/vcache.v
index e2914f5130..aa958460a0 100644
--- a/vlib/v/vcache/vcache.v
+++ b/vlib/v/vcache/vcache.v
@@ -41,15 +41,13 @@ pub fn new_cache_manager(opts []string) CacheManager {
 	}
 	dlog(@FN, 'vcache_basepath: $vcache_basepath | opts:\n     $opts')
 	if !os.is_dir(vcache_basepath) {
-		os.mkdir_all(vcache_basepath) or { panic(err.msg) }
+		os.mkdir_all(vcache_basepath) or { panic(err) }
 		readme_content := 'This folder contains cached build artifacts from the V build system.
 		|You can safely delete it, if it is getting too large.
 		|It will be recreated the next time you compile something with V.
 		|You can change its location with the VCACHE environment variable.
 		'.strip_margin()
-		os.write_file(os.join_path(vcache_basepath, 'README.md'), readme_content) or {
-			panic(err.msg)
-		}
+		os.write_file(os.join_path(vcache_basepath, 'README.md'), readme_content) or { panic(err) }
 	}
 	original_vopts := opts.join('|')
 	return CacheManager{
@@ -78,7 +76,7 @@ pub fn (mut cm CacheManager) key2cpath(key string) string {
 		cprefix_folder := os.join_path(cm.basepath, prefix)
 		cpath = os.join_path(cprefix_folder, khash)
 		if !os.is_dir(cprefix_folder) {
-			os.mkdir_all(cprefix_folder) or { panic(err.msg) }
+			os.mkdir_all(cprefix_folder) or { panic(err) }
 			os.chmod(cprefix_folder, 0o777)
 		}
 		dlog(@FN, 'new hk')
diff --git a/vlib/vweb/assets/assets.v b/vlib/vweb/assets/assets.v
index 7124941c40..1240e4123c 100644
--- a/vlib/vweb/assets/assets.v
+++ b/vlib/vweb/assets/assets.v
@@ -96,10 +96,10 @@ fn (am AssetManager) combine(asset_type string, to_file bool) string {
 		return out
 	}
 	if !os.is_dir(am.cache_dir) {
-		os.mkdir(am.cache_dir) or { panic(err.msg) }
+		os.mkdir(am.cache_dir) or { panic(err) }
 	}
-	mut file := os.create(out_file) or { panic(err.msg) }
-	file.write(out.bytes()) or { panic(err.msg) }
+	mut file := os.create(out_file) or { panic(err) }
+	file.write(out.bytes()) or { panic(err) }
 	file.close()
 	return out_file
 }
diff --git a/vlib/vweb/assets/assets_test.v b/vlib/vweb/assets/assets_test.v
index 7b3dead8af..6170f3ce47 100644
--- a/vlib/vweb/assets/assets_test.v
+++ b/vlib/vweb/assets/assets_test.v
@@ -6,7 +6,7 @@ import os
 // unique cache dirs are needed per test function.
 fn clean_cache_dir(dir string) {
 	if os.is_dir(dir) {
-		os.rmdir_all(dir) or { panic(err.msg) }
+		os.rmdir_all(dir) or { panic(err) }
 	}
 }
 
@@ -21,10 +21,10 @@ fn cache_dir(test_name string) string {
 fn get_test_file_path(file string) string {
 	path := os.join_path(base_cache_dir(), file)
 	if !os.is_dir(base_cache_dir()) {
-		os.mkdir_all(base_cache_dir()) or { panic(err.msg) }
+		os.mkdir_all(base_cache_dir()) or { panic(err) }
 	}
 	if !os.exists(path) {
-		os.write_file(path, get_test_file_contents(file)) or { panic(err.msg) }
+		os.write_file(path, get_test_file_contents(file)) or { panic(err) }
 	}
 	return path
 }
diff --git a/vlib/vweb/tests/vweb_test.v b/vlib/vweb/tests/vweb_test.v
index 93cff318ac..37ec2ea65b 100644
--- a/vlib/vweb/tests/vweb_test.v
+++ b/vlib/vweb/tests/vweb_test.v
@@ -102,14 +102,14 @@ fn assert_common_http_headers(x http.Response) {
 }
 
 fn test_http_client_index() {
-	x := http.get('http://127.0.0.1:$sport/') or { panic(err.msg) }
+	x := http.get('http://127.0.0.1:$sport/') or { panic(err) }
 	assert_common_http_headers(x)
 	assert x.headers['Content-Type'] == 'text/plain'
 	assert x.text == 'Welcome to VWeb'
 }
 
 fn test_http_client_chunk_transfer() {
-	x := http.get('http://127.0.0.1:$sport/chunk') or { panic(err.msg) }
+	x := http.get('http://127.0.0.1:$sport/chunk') or { panic(err) }
 	assert_common_http_headers(x)
 	assert x.headers['Transfer-Encoding'] == 'chunked'
 	assert x.text == 'Lorem ipsum dolor sit amet, consetetur sadipscing'
@@ -122,45 +122,45 @@ fn test_http_client_404() {
 		'http://127.0.0.1:$sport/unknown',
 	]
 	for url in url_404_list {
-		res := http.get(url) or { panic(err.msg) }
+		res := http.get(url) or { panic(err) }
 		assert res.status_code == 404
 	}
 }
 
 fn test_http_client_simple() {
-	x := http.get('http://127.0.0.1:$sport/simple') or { panic(err.msg) }
+	x := http.get('http://127.0.0.1:$sport/simple') or { panic(err) }
 	assert_common_http_headers(x)
 	assert x.headers['Content-Type'] == 'text/plain'
 	assert x.text == 'A simple result'
 }
 
 fn test_http_client_html_page() {
-	x := http.get('http://127.0.0.1:$sport/html_page') or { panic(err.msg) }
+	x := http.get('http://127.0.0.1:$sport/html_page') or { panic(err) }
 	assert_common_http_headers(x)
 	assert x.headers['Content-Type'] == 'text/html'
 	assert x.text == '<h1>ok</h1>'
 }
 
 fn test_http_client_settings_page() {
-	x := http.get('http://127.0.0.1:$sport/bilbo/settings') or { panic(err.msg) }
+	x := http.get('http://127.0.0.1:$sport/bilbo/settings') or { panic(err) }
 	assert_common_http_headers(x)
 	assert x.text == 'username: bilbo'
 	//
-	y := http.get('http://127.0.0.1:$sport/kent/settings') or { panic(err.msg) }
+	y := http.get('http://127.0.0.1:$sport/kent/settings') or { panic(err) }
 	assert_common_http_headers(y)
 	assert y.text == 'username: kent'
 }
 
 fn test_http_client_user_repo_settings_page() {
-	x := http.get('http://127.0.0.1:$sport/bilbo/gostamp/settings') or { panic(err.msg) }
+	x := http.get('http://127.0.0.1:$sport/bilbo/gostamp/settings') or { panic(err) }
 	assert_common_http_headers(x)
 	assert x.text == 'username: bilbo | repository: gostamp'
 	//
-	y := http.get('http://127.0.0.1:$sport/kent/golang/settings') or { panic(err.msg) }
+	y := http.get('http://127.0.0.1:$sport/kent/golang/settings') or { panic(err) }
 	assert_common_http_headers(y)
 	assert y.text == 'username: kent | repository: golang'
 	//
-	z := http.get('http://127.0.0.1:$sport/missing/golang/settings') or { panic(err.msg) }
+	z := http.get('http://127.0.0.1:$sport/missing/golang/settings') or { panic(err) }
 	assert z.status_code == 404
 }
 
@@ -175,9 +175,7 @@ fn test_http_client_json_post() {
 		age: 123
 	}
 	json_for_ouser := json.encode(ouser)
-	mut x := http.post_json('http://127.0.0.1:$sport/json_echo', json_for_ouser) or {
-		panic(err.msg)
-	}
+	mut x := http.post_json('http://127.0.0.1:$sport/json_echo', json_for_ouser) or { panic(err) }
 	$if debug_net_socket_client ? {
 		eprintln('/json_echo endpoint response: $x')
 	}
@@ -186,7 +184,7 @@ fn test_http_client_json_post() {
 	nuser := json.decode(User, x.text) or { User{} }
 	assert '$ouser' == '$nuser'
 	//
-	x = http.post_json('http://127.0.0.1:$sport/json', json_for_ouser) or { panic(err.msg) }
+	x = http.post_json('http://127.0.0.1:$sport/json', json_for_ouser) or { panic(err) }
 	$if debug_net_socket_client ? {
 		eprintln('/json endpoint response: $x')
 	}
diff --git a/vlib/vweb/vweb.v b/vlib/vweb/vweb.v
index 8c67dcea1e..2f0be31b7c 100644
--- a/vlib/vweb/vweb.v
+++ b/vlib/vweb/vweb.v
@@ -594,7 +594,7 @@ pub fn (mut ctx Context) parse_multipart_form(s string, b string) {
 }
 
 fn (mut ctx Context) scan_static_directory(directory_path string, mount_path string) {
-	files := os.ls(directory_path) or { panic(err.msg) }
+	files := os.ls(directory_path) or { panic(err) }
 	if files.len > 0 {
 		for file in files {
 			full_path := directory_path + '/' + file
@@ -613,7 +613,7 @@ fn (mut ctx Context) scan_static_directory(directory_path string, mount_path str
 }
 
 // Handles a directory static
-// If `root` is set the mount path for the dir will be in '/' 
+// If `root` is set the mount path for the dir will be in '/'
 pub fn (mut ctx Context) handle_static(directory_path string, root bool) bool {
 	if ctx.done || !os.exists(directory_path) {
 		return false
@@ -629,7 +629,7 @@ pub fn (mut ctx Context) handle_static(directory_path string, root bool) bool {
 }
 
 // Serves a file static
-// `url` is the access path on the site, `file_path` is the real path to the file, `mime_type` is the file type 
+// `url` is the access path on the site, `file_path` is the real path to the file, `mime_type` is the file type
 pub fn (mut ctx Context) serve_static(url string, file_path string, mime_type string) {
 	ctx.static_files[url] = file_path
 	ctx.static_mime_types[url] = mime_type
diff --git a/vlib/x/ttf/common.v b/vlib/x/ttf/common.v
index 7c72d3e998..370c333d04 100644
--- a/vlib/x/ttf/common.v
+++ b/vlib/x/ttf/common.v
@@ -10,7 +10,7 @@ module ttf
 *
 * Note:
 *
-* TODO: 
+* TODO:
 **********************************************************************/
 import os
 import math
@@ -93,17 +93,17 @@ pub fn (mut bmp BitMap) save_as_ppm(file_name string) {
 
 	bmp.format_texture()
 	npixels := bmp.width * bmp.height
-	mut f_out := os.create(file_name) or { panic(err.msg) }
-	f_out.writeln('P3') or { panic(err.msg) }
-	f_out.writeln('$bmp.width $bmp.height') or { panic(err.msg) }
-	f_out.writeln('255') or { panic(err.msg) }
+	mut f_out := os.create(file_name) or { panic(err) }
+	f_out.writeln('P3') or { panic(err) }
+	f_out.writeln('$bmp.width $bmp.height') or { panic(err) }
+	f_out.writeln('255') or { panic(err) }
 	for i in 0 .. npixels {
 		pos := i * bmp.bp
 		unsafe {
 			c_r := bmp.buf[pos]
 			c_g := bmp.buf[pos + 1]
 			c_b := bmp.buf[pos + 2]
-			f_out.write_str('$c_r $c_g $c_b ') or { panic(err.msg) }
+			f_out.write_str('$c_r $c_g $c_b ') or { panic(err) }
 		}
 	}
 	f_out.close()
@@ -127,7 +127,7 @@ pub fn (mut bmp BitMap) get_raw_bytes() []byte {
 }
 
 pub fn (mut bmp BitMap) save_raw_data(file_name string) {
-	os.write_file_array(file_name, bmp.get_raw_bytes()) or { panic(err.msg) }
+	os.write_file_array(file_name, bmp.get_raw_bytes()) or { panic(err) }
 }
 
 //
diff --git a/vlib/x/ttf/ttf_test.v b/vlib/x/ttf/ttf_test.v
index 837c322d9b..9567dca990 100644
--- a/vlib/x/ttf/ttf_test.v
+++ b/vlib/x/ttf/ttf_test.v
@@ -13,7 +13,7 @@ import strings
 * Note:
 * use `v -d create_data vlib/x/ttf/ttf_test.v` to generate binary data for this test file
 *
-* TODO: 
+* TODO:
 * - manage text directions R to L
 **********************************************************************/
 const font_path = 'Qarmic_sans_Abridged.ttf'
@@ -156,13 +156,13 @@ fn save_raw_data_as_array(buf_bin []byte, file_name string) {
 	for x in buf_bin {
 		buf.write_string('0x${x:02x},')
 	}
-	os.write_file_array(file_name, buf.buf) or { panic(err.msg) }
+	os.write_file_array(file_name, buf.buf) or { panic(err) }
 }
 
 fn test_main() {
 	mut tf := ttf.TTF_File{}
 	$if create_data ? {
-		tf.buf = os.read_bytes(font_path) or { panic(err.msg) }
+		tf.buf = os.read_bytes(font_path) or { panic(err) }
 		println('TrueTypeFont file [$font_path] len: $tf.buf.len')
 		save_raw_data_as_array(tf.buf, 'test_ttf_Font_arr.bin')
 	} $else {
@@ -200,7 +200,7 @@ fn test_main() {
 	$if create_data ? {
 		bmp.save_as_ppm('test_ttf.ppm')
 		bmp.save_raw_data('test_ttf.bin')
-		test_buf = os.read_bytes('test_ttf.bin') or { panic(err.msg) }
+		test_buf = os.read_bytes('test_ttf.bin') or { panic(err) }
 	}
 
 	ram_buf := bmp.get_raw_bytes()
diff --git a/vlib/x/websocket/tests/autobahn/autobahn_client.v b/vlib/x/websocket/tests/autobahn/autobahn_client.v
index 7228428e08..6b94e7fd67 100644
--- a/vlib/x/websocket/tests/autobahn/autobahn_client.v
+++ b/vlib/x/websocket/tests/autobahn/autobahn_client.v
@@ -29,5 +29,5 @@ fn on_message(mut ws websocket.Client, msg &websocket.Message) ? {
 		// We just wanna pass text and binary message back to autobahn
 		return
 	}
-	ws.write(msg.payload, msg.opcode) or { panic(err.msg) }
+	ws.write(msg.payload, msg.opcode) or { panic(err) }
 }
diff --git a/vlib/x/websocket/tests/autobahn/autobahn_client_wss.v b/vlib/x/websocket/tests/autobahn/autobahn_client_wss.v
index 5886d40e95..7d015ea9e8 100644
--- a/vlib/x/websocket/tests/autobahn/autobahn_client_wss.v
+++ b/vlib/x/websocket/tests/autobahn/autobahn_client_wss.v
@@ -31,5 +31,5 @@ fn on_message(mut ws websocket.Client, msg &websocket.Message) ? {
 		// We just wanna pass text and binary message back to autobahn
 		return
 	}
-	ws.write(msg.payload, msg.opcode) or { panic(err.msg) }
+	ws.write(msg.payload, msg.opcode) or { panic(err) }
 }
diff --git a/vlib/x/websocket/tests/autobahn/autobahn_server.v b/vlib/x/websocket/tests/autobahn/autobahn_server.v
index e8b6455179..d6b41dceb2 100644
--- a/vlib/x/websocket/tests/autobahn/autobahn_server.v
+++ b/vlib/x/websocket/tests/autobahn/autobahn_server.v
@@ -6,7 +6,7 @@ import x.websocket
 fn main() {
 	mut s := websocket.new_server(9002, '/')
 	s.on_message(on_message)
-	s.listen() or { panic(err.msg) }
+	s.listen() or { panic(err) }
 }
 
 fn handle_case(case_nr int) ? {
@@ -23,5 +23,5 @@ fn on_message(mut ws websocket.Client, msg &websocket.Message) ? {
 		// We just wanna pass text and binary message back to autobahn
 		return
 	}
-	ws.write(msg.payload, msg.opcode) or { panic(err.msg) }
+	ws.write(msg.payload, msg.opcode) or { panic(err) }
 }
diff --git a/vlib/x/websocket/tests/autobahn/local_run/autobahn_client.v b/vlib/x/websocket/tests/autobahn/local_run/autobahn_client.v
index e9b77ab081..1d29e27b07 100644
--- a/vlib/x/websocket/tests/autobahn/local_run/autobahn_client.v
+++ b/vlib/x/websocket/tests/autobahn/local_run/autobahn_client.v
@@ -29,5 +29,5 @@ fn on_message(mut ws websocket.Client, msg &websocket.Message) ? {
 		// We just wanna pass text and binary message back to autobahn
 		return
 	}
-	ws.write(msg.payload, msg.opcode) or { panic(err.msg) }
+	ws.write(msg.payload, msg.opcode) or { panic(err) }
 }
diff --git a/vlib/x/websocket/tests/autobahn/local_run/autobahn_client_wss.v b/vlib/x/websocket/tests/autobahn/local_run/autobahn_client_wss.v
index 5886d40e95..7d015ea9e8 100644
--- a/vlib/x/websocket/tests/autobahn/local_run/autobahn_client_wss.v
+++ b/vlib/x/websocket/tests/autobahn/local_run/autobahn_client_wss.v
@@ -31,5 +31,5 @@ fn on_message(mut ws websocket.Client, msg &websocket.Message) ? {
 		// We just wanna pass text and binary message back to autobahn
 		return
 	}
-	ws.write(msg.payload, msg.opcode) or { panic(err.msg) }
+	ws.write(msg.payload, msg.opcode) or { panic(err) }
 }
diff --git a/vlib/x/websocket/websocket_client.v b/vlib/x/websocket/websocket_client.v
index 0bfcfc0093..6faf91b2a8 100644
--- a/vlib/x/websocket/websocket_client.v
+++ b/vlib/x/websocket/websocket_client.v
@@ -146,7 +146,7 @@ pub fn (mut ws Client) listen() ? {
 					ws.logger.error('error in message callback sending PONG: $err')
 					ws.send_error_event('error in message callback sending PONG: $err')
 					if ws.panic_on_callback {
-						panic(err.msg)
+						panic(err)
 					}
 					continue
 				}
diff --git a/vlib/x/websocket/websocket_test.v b/vlib/x/websocket/websocket_test.v
index 7a0773c742..1a4e7f5b0e 100644
--- a/vlib/x/websocket/websocket_test.v
+++ b/vlib/x/websocket/websocket_test.v
@@ -40,8 +40,8 @@ fn start_server(listen_port int) ? {
 	}) ?
 	s.on_message(fn (mut ws websocket.Client, msg &websocket.Message) ? {
 		match msg.opcode {
-			.pong { ws.write_str('pong') or { panic(err.msg) } }
-			else { ws.write(msg.payload, msg.opcode) or { panic(err.msg) } }
+			.pong { ws.write_str('pong') or { panic(err) } }
+			else { ws.write(msg.payload, msg.opcode) or { panic(err) } }
 		}
 	})
 
@@ -96,7 +96,7 @@ fn ws_test(uri string) ? {
 	}
 	// sleep to give time to recieve response before asserts
 	time.sleep(1500 * time.millisecond)
-	// We expect at least 2 pongs, one sent directly and one indirectly 
+	// We expect at least 2 pongs, one sent directly and one indirectly
 	assert test_results.nr_pong_received >= 2
 	assert test_results.nr_messages == 2
 }