Segfault/Trap when using -show-system-calls that generate long link commands

[spahnke]

Context

Odin: dev-2025-02-nightly:584fdc0
OS: macOS Sequoia 15.3.0 (build 24D60, kernel 24.3.0)
CPU: Apple M4
RAM: 24576 MiB
Backend: LLVM 18.1.8

Steps to Reproduce

This started happening after updating to the newest compiler version with one of my projects and I struggled a bit to reproduce minimally because it seems to be related to link command length. If you run

odin build . -out:long-executable-name -sanitize:address -show-system-calls

for the input file

package main

import "base:runtime"
import "core:c"
import "core:encoding/ansi"
import "core:fmt"
import "core:log"
import "core:image/png"
import "core:mem"
import "core:mem/virtual"
import "core:strings"
import "vendor:glfw"
import gl "vendor:OpenGL"

main :: proc() {
    glfw.Init()
}

you get a segfault. If you make the build command shorter (e.g. changing the executable name, taking away the -sanitize option), or remove an import, or even comment the line of code in main, it doesn't segfault anymore but traps. If you make it yet shorter it works.

I built from source to run it through the debugger and LLDB reports the error here:

(lldb) run build . -out:long-executable-name -sanitize:address -show-system-calls
Process 73993 launched: '/Users/sebastian/dev/Odin/odin' (arm64)
[SYSTEM CALL] ld-link
Process 73993 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x696c2f7765726265)
    frame #0: 0x0000000100004704 odin`gb_strlen(str="") at gb.h:3653:8
   3650                 return 0;
   3651         }
   3652         while (cast(uintptr)str % sizeof(usize)) {
-> 3653                 if (!*str)
   3654                         return str - begin;
   3655                 str++;
   3656         }
Target 0: (odin) stopped.
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x696c2f7765726265)
  * frame #0: 0x0000000100004704 odin`gb_strlen(str="") at gb.h:3653:8
    frame #1: 0x000000010000bc18 odin`gb__print_string(text="", max_len=8192, info=0x000000016fdfa4b8, str="") at gb.h:5907:9
    frame #2: 0x00000001000065ec odin`gb_snprintf_va(text="", max_len=8192, fmt="s\n\n", va="b -lm   -L/ -framework System  -framework Cocoa  -framework IOKit  -framework OpenGL  /Users/sebastian/dev/Odin/vendor/glfw/lib/darwin/libglfw3.a   -target arm64-apple-macosx   -fsanitize=address  -no-pie -e _main -Wl,-rpath,@loader_path  \n\n") at gb.h:6192:10
    frame #3: 0x00000001000026cc odin`::gb_printf_err(const char *, ...) [inlined] gb_fprintf_va(f=0x000000010034a830, fmt="%s\n\n", va="ebrew/lib -lm   -L/ -framework System  -framework Cocoa  -framework IOKit  -framework OpenGL  /Users/sebastian/dev/Odin/vendor/glfw/lib/darwin/libglfw3.a   -target arm64-apple-macosx   -fsanitize=address  -no-pie -e _main -Wl,-rpath,@loader_path  \n\n") at gb.h:5848:9
    frame #4: 0x0000000100002550 odin`::gb_printf_err(const char *, ...) [inlined] gb_printf_err_va(fmt="%s\n\n", va="ebrew/lib -lm   -L/ -framework System  -framework Cocoa  -framework IOKit  -framework OpenGL  /Users/sebastian/dev/Odin/vendor/glfw/lib/darwin/libglfw3.a   -target arm64-apple-macosx   -fsanitize=address  -no-pie -e _main -Wl,-rpath,@loader_path  \n\n") at gb.h:5836:9
    frame #5: 0x00000001000024a4 odin`gb_printf_err(fmt="%s\n\n") at gb.h:5797:8

[spahnke]

For reference this is the command printed when it still works (using -out:probe):

clang -Wno-unused-command-line-argument "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-os-13744c4a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-reflect-13744faa0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-compress-13744d0a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-time-13744caa0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-libc-1374506a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-compress_zlib-13744d3a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-bytes-13744dfa0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-glfw_bindings-137450fa0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-png-13744b2a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-glfw-13744bea0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-datetime-13744e2a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-vendor_gl-13744c1a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-strconv_decimal-1374500a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-darwin-13744eea0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-posix-13744f1a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-runtime-13744a0a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-utf8-13744d9a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-unicode-13744e8a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-strings-13744bba0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-vulkan-1374512a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-mem-13744b5a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-image-13744d6a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-sys_windows-1374518a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-xlib-137451ba0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-utf16-1374503a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-main-13744a3a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-hash-13744dca0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-ansi-13744a9a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-unix-13744e5a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-simd-13744eba0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-137449d28.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-log-13744afa0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-io-13744c7a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-math-13744f4a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-bufio-13744cda0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-strconv-13744fda0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-math_bits-13744f7a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-fmt-13744aca0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-objc_Foundation-1374515a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-mem_virtual-13744b8a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe--137450ca0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-sync-1374509a0.o" "/var/folders/gb/yjg0krmn6qv7q8vg674bkhqc0000gn/T//probe-c-13744a6a0.o"  -o "/Users/sebastian/dev/probe/probe"  -Wl,-syslibroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -L/usr/local/lib -L/opt/homebrew/lib -lm   -L/ -framework System  -framework Cocoa  -framework IOKit  -framework OpenGL  /Users/sebastian/dev/Odin/vendor/glfw/lib/darwin/libglfw3.a   -target arm64-apple-macosx   -fsanitize=address  -no-pie -e _main -Wl,-rpath,@loader_path