From 81b4fdcadcf43a2aa3f6f723c780bacf2abf91b3 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Wed, 11 Mar 2026 13:49:20 +0300
Subject: [PATCH] builder: addr2line: 'v': No such file, instead of meaningful
 output, when build fails due to internal bug (fixes #20768)

---
 vlib/builtin/backtraces_nix.c.v              | 28 +++++++++++++-
 vlib/v/tests/backtrace_addr2line_path_test.v | 39 ++++++++++++++++++++
 2 files changed, 66 insertions(+), 1 deletion(-)
 create mode 100644 vlib/v/tests/backtrace_addr2line_path_test.v

diff --git a/vlib/builtin/backtraces_nix.c.v b/vlib/builtin/backtraces_nix.c.v
index c1dfdf952..529813aa1 100644
--- a/vlib/builtin/backtraces_nix.c.v
+++ b/vlib/builtin/backtraces_nix.c.v
@@ -38,6 +38,29 @@ fn print_backtrace_skipping_top_frames_bsd(skipframes int) bool {
 }
 
 fn C.tcc_backtrace(fmt &char) i32
+
+fn backtrace_current_executable_name() string {
+	args := arguments()
+	if args.len == 0 {
+		return ''
+	}
+	return args[0]
+}
+
+fn backtrace_addr2line_executable(executable string, current_executable_name string) string {
+	if executable.len == 0 {
+		return '/proc/self/exe'
+	}
+	if executable.contains('/') {
+		return executable
+	}
+	if current_executable_name.len > 0
+		&& executable.all_after_last('/') == current_executable_name.all_after_last('/') {
+		return '/proc/self/exe'
+	}
+	return executable
+}
+
 @[direct_array_access]
 fn print_backtrace_skipping_top_frames_linux(skipframes int) bool {
 	$if android {
@@ -60,6 +83,7 @@ fn print_backtrace_skipping_top_frames_linux(skipframes int) bool {
 					eprintln('Some libc implementations like musl simply do not provide it.')
 					return false
 				} $else {
+					current_executable_name := backtrace_current_executable_name()
 					buffer := [100]voidptr{}
 					nr_ptrs := C.backtrace(&buffer[0], 100)
 					if nr_ptrs < 2 {
@@ -72,9 +96,11 @@ fn print_backtrace_skipping_top_frames_linux(skipframes int) bool {
 					for i in 0 .. nr_actual_frames {
 						sframe := unsafe { tos2(&u8(csymbols[i])) }
 						executable := sframe.all_before('(')
+						addr2line_executable := backtrace_addr2line_executable(executable,
+							current_executable_name)
 						addr := sframe.all_after('[').all_before(']')
 						beforeaddr := sframe.all_before('[')
-						cmd := 'addr2line -e ' + executable + ' ' + addr
+						cmd := 'addr2line -e ' + addr2line_executable + ' ' + addr
 						// taken from os, to avoid depending on the os module inside builtin.v
 						f := C.popen(&char(cmd.str), c'r')
 						if f == unsafe { nil } {
diff --git a/vlib/v/tests/backtrace_addr2line_path_test.v b/vlib/v/tests/backtrace_addr2line_path_test.v
new file mode 100644
index 000000000..6551b95b0
--- /dev/null
+++ b/vlib/v/tests/backtrace_addr2line_path_test.v
@@ -0,0 +1,39 @@
+import os
+
+const vexe = @VEXE
+
+fn test_print_backtrace_does_not_pass_a_bare_main_binary_name_to_addr2line() {
+	base_dir := os.join_path(os.vtmp_dir(), 'backtrace_addr2line_path_test_${os.getpid()}')
+	bin_dir := os.join_path(base_dir, 'bin')
+	run_dir := os.join_path(base_dir, 'run')
+	source_path := os.join_path(base_dir, 'backtrace_addr2line_probe.v')
+	exe_name := 'backtrace_addr2line_probe'
+	exe_path := os.join_path(bin_dir, exe_name)
+	old_path := os.getenv('PATH')
+	old_wd := os.getwd()
+	os.rmdir_all(base_dir) or {}
+	os.mkdir_all(bin_dir)!
+	os.mkdir_all(run_dir)!
+	defer {
+		os.chdir(old_wd) or {}
+		os.setenv('PATH', old_path, true)
+		os.rmdir_all(base_dir) or {}
+	}
+	helper_source := [
+		'fn main() {',
+		"\teprintln('backtrace_addr2line_probe')",
+		'\tprint_backtrace()',
+		'}',
+	].join_lines()
+	os.write_file(source_path, helper_source)!
+	compile_cmd := '${os.quoted_path(vexe)} -g -o ${os.quoted_path(exe_path)} ${os.quoted_path(source_path)}'
+	compile_res := os.execute(compile_cmd)
+	assert compile_res.exit_code == 0, 'compilation failed: ${compile_res.output}'
+	os.setenv('PATH', '${bin_dir}${os.path_delimiter}${old_path}', true)
+	os.chdir(run_dir)!
+	run_res := os.execute('${exe_name} 2>&1')
+	assert run_res.exit_code == 0, 'execution failed: ${run_res.output}'
+	assert run_res.output.contains('backtrace_addr2line_probe')
+	assert !run_res.output.contains('addr2line:'), run_res.output
+	assert !run_res.output.contains('No such file'), run_res.output
+}
-- 
2.39.5