Compiler segfaults instead of printing an error

[Jarred-Sumner]

Zig Version

0.14.1

Steps to Reproduce and Observed Behavior

1. git init bun-temp && cd bun-temp && git remote add origin https://github.com/oven-sh/bun.git && git fetch origin 8f0d75f00a6889adcf4d1fdb522b81b694b02889 --depth 1 && git checkout 8f0d75f00a6889adcf4d1fdb522b81b694b02889
2. bun run build

error: the following command terminated unexpectedly:
<path-to-zig>/zig build-obj -freference-trace=16 -fllvm -fno-lld -fno-strip -fno-omit-frame-pointer -fsanitize-address -fPIC -ODebug -target aarch64-macos.13.0-none -mcpu apple_m1 --dep bun -Mroot=<bun-folder>/src/main.zig --dep bun --dep build_options --dep translated-c-headers --dep zlib-internal --dep async --dep ZigGeneratedClasses --dep ResolvedSourceTag --dep ErrorCode --dep completions-bash --dep completions-zsh --dep completions-fish -Mbun=<bun-folder>/src/bun.zig --dep bun --dep build_options --dep translated-c-headers --dep zlib-internal --dep async --dep ZigGeneratedClasses --dep ResolvedSourceTag --dep ErrorCode --dep completions-bash --dep completions-zsh --dep completions-fish -Mbuild_options=<cache>/zig/local/c/2ce8a8d113a0d4a9e2856aac727a86c7/options.zig --dep bun --dep build_options --dep translated-c-headers --dep zlib-internal --dep async --dep ZigGeneratedClasses --dep ResolvedSourceTag --dep ErrorCode --dep completions-bash --dep completions-zsh --dep completions-fish -Mtranslated-c-headers=<cache>/zig/local/o/24a6e346caf804a6157e36c5c0630ba8/c-headers-for-zig.zig --dep bun --dep build_options --dep translated-c-headers --dep zlib-internal --dep async --dep ZigGeneratedClasses --dep ResolvedSourceTag --dep ErrorCode --dep completions-bash --dep completions-zsh --dep completions-fish -Mzlib-internal=<bun-folder>/src/deps/zlib.posix.zig --dep bun --dep build_options --dep translated-c-headers --dep zlib-internal --dep async --dep ZigGeneratedClasses --dep ResolvedSourceTag --dep ErrorCode --dep completions-bash --dep completions-zsh --dep completions-fish -Masync=<bun-folder>/src/async/posix_event_loop.zig --dep bun --dep build_options --dep translated-c-headers --dep zlib-internal --dep async --dep ZigGeneratedClasses --dep ResolvedSourceTag --dep ErrorCode --dep completions-bash --dep completions-zsh --dep completions-fish -MZigGeneratedClasses=<build-folder>/codegen/ZigGeneratedClasses.zig --dep bun --dep build_options --dep translated-c-headers --dep zlib-internal --dep async --dep ZigGeneratedClasses --dep ResolvedSourceTag --dep ErrorCode --dep completions-bash --dep completions-zsh --dep completions-fish -MResolvedSourceTag=<build-folder>/codegen/ResolvedSourceTag.zig --dep bun --dep build_options --dep translated-c-headers --dep zlib-internal --dep async --dep ZigGeneratedClasses --dep ResolvedSourceTag --dep ErrorCode --dep completions-bash --dep completions-zsh --dep completions-fish -MErrorCode=<build-folder>/codegen/ErrorCode.zig --dep bun --dep build_options --dep translated-c-headers --dep zlib-internal --dep async --dep ZigGeneratedClasses --dep ResolvedSourceTag --dep ErrorCode --dep completions-bash --dep completions-zsh --dep completions-fish -Mcompletions-bash=<bun-folder>/completions/bun.bash --dep bun --dep build_options --dep translated-c-headers --dep zlib-internal --dep async --dep ZigGeneratedClasses --dep ResolvedSourceTag --dep ErrorCode --dep completions-bash --dep completions-zsh --dep completions-fish -Mcompletions-zsh=<bun-folder>/completions/bun.zsh --dep bun --dep build_options --dep translated-c-headers --dep zlib-internal --dep async --dep ZigGeneratedClasses --dep ResolvedSourceTag --dep ErrorCode --dep completions-bash --dep completions-zsh --dep completions-fish -Mcompletions-fish=<bun-folder>/completions/bun.fish -lc++ -lc --cache-dir <cache>/zig/local --global-cache-dir <cache>/zig/global --name bun-debug -fno-compiler-rt -fno-ubsan-rt --zig-lib-dir /<path-to-zig>/lib/ --listen=-
Build Summary: 2/5 steps succeeded; 1 failed
obj transitive failure
├─ zig build-obj bun-debug Debug aarch64-macos.13.0-none failure
│  ├─ options cached
│  └─ translate-c cached 34ms MaxRSS:35M
└─ install generated to bun-zig.o transitive failure
   └─ zig build-obj bun-debug Debug aarch64-macos.13.0-none (+2 more reused dependencies)
error: the following build command failed with exit code 1:
<cache>/zig/local/o/73a26231e1c9ebb645536fd66e30e934/build /<path-to-zig>/zig /<path-to-zig>/lib <bun-folder> <cache>/zig/local <cache>/zig/global --seed 0xa5421364 -Zf3a2228e956a080d obj --prefix <build-folder> -Dobj_format=obj -Dtarget=aarch64-macos-none -Doptimize=Debug -Dcpu=apple_m1 -Denable_logs=true -Denable_asan=true -Dversion=1.2.16 -Dreported_nodejs_version=22.6.0 -Dcanary=1 -Dcodegen_path=<build-folder>/codegen -Dcodegen_embed=false --prominent-compile-errors --summary all -Dsha=504f9b6c85be00427305ffa9afcc609e4ea2556b
FAILED: bun-zig.o <build-folder>/bun-zig.o
cd <bun-folder> && /<path-to-zig>/zig build obj --cache-dir <cache>/zig/local --global-cache-dir <cache>/zig/global --zig-lib-dir /<path-to-zig>/lib --prefix <build-folder> -Dobj_format=obj -Dtarget=aarch64-macos-none -Doptimize=Debug -Dcpu=apple_m1 -Denable_logs=true -Denable_asan=true -Dversion=1.2.16 -Dreported_nodejs_version=22.6.0 -Dcanary=1 -Dcodegen_path=<build-folder>/codegen -Dcodegen_embed=false --prominent-compile-errors --summary all -Dsha=504f9b6c85be00427305ffa9afcc609e4ea2556b
ninja: build stopped: subcommand failed.
  cmake took 0.53 seconds
  Command exited: code 1
error: script "build:debug" exited with code 1
error: script "build" exited with code 1

If you run the printed build-obj command with a debug build of Zig it should produce a more useful stack trace. I suggest running bun run build once to get the codegen scripts and everything into a state where it can build, then copy-pasting the command on your local machine replacing the path that contains vendor/zig to your debug build of Zig. Or you could symlink vendor/zig to your local zig folder.

Here's what lldb reports:

* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x52963389c)
    frame #0: 0x0000000104de2d3c zig`codegen.llvm.Object.lowerDebugType + 9696
zig`codegen.llvm.Object.lowerDebugType:
->  0x104de2d3c <+9696>: ldr    w20, [x8, w24, uxtw #2]
    0x104de2d40 <+9700>: str    w20, [sp, #0x9e0]
    0x104de2d44 <+9704>: add    x0, sp, #0xd10
    0x104de2d48 <+9708>: mov    x1, x20
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x52963389c)
  * frame #0: 0x0000000104de2d3c zig`codegen.llvm.Object.lowerDebugType + 9696
    frame #1: 0x0000000104de56b0 zig`codegen.llvm.Object.lowerDebugType + 20308
    frame #2: 0x0000000104de3fbc zig`codegen.llvm.Object.lowerDebugType + 14432
    frame #3: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #4: 0x0000000104de56b0 zig`codegen.llvm.Object.lowerDebugType + 20308
    frame #5: 0x0000000104de3fbc zig`codegen.llvm.Object.lowerDebugType + 14432
    frame #6: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #7: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #8: 0x0000000104de56b0 zig`codegen.llvm.Object.lowerDebugType + 20308
    frame #9: 0x0000000104de3fbc zig`codegen.llvm.Object.lowerDebugType + 14432
    frame #10: 0x0000000104de358c zig`codegen.llvm.Object.lowerDebugType + 11824
    frame #11: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #12: 0x0000000104de56b0 zig`codegen.llvm.Object.lowerDebugType + 20308
    frame #13: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #14: 0x0000000104de56b0 zig`codegen.llvm.Object.lowerDebugType + 20308
    frame #15: 0x0000000104de3fbc zig`codegen.llvm.Object.lowerDebugType + 14432
    frame #16: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #17: 0x0000000104de3fbc zig`codegen.llvm.Object.lowerDebugType + 14432
    frame #18: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #19: 0x0000000104de56b0 zig`codegen.llvm.Object.lowerDebugType + 20308
    frame #20: 0x0000000104de204c zig`codegen.llvm.Object.lowerDebugType + 6384
    frame #21: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #22: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #23: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #24: 0x0000000104de56b0 zig`codegen.llvm.Object.lowerDebugType + 20308
    frame #25: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #26: 0x0000000104de3fbc zig`codegen.llvm.Object.lowerDebugType + 14432
    frame #27: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #28: 0x0000000104de56b0 zig`codegen.llvm.Object.lowerDebugType + 20308
    frame #29: 0x0000000104de204c zig`codegen.llvm.Object.lowerDebugType + 6384
    frame #30: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #31: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #32: 0x0000000104de56b0 zig`codegen.llvm.Object.lowerDebugType + 20308
    frame #33: 0x0000000104de2e48 zig`codegen.llvm.Object.lowerDebugType + 9964
    frame #34: 0x0000000104de56b0 zig`codegen.llvm.Object.lowerDebugType + 20308
    frame #35: 0x0000000105339590 zig`codegen.llvm.FuncGen.genBody + 51420
    frame #36: 0x000000010532b704 zig`codegen.llvm.Object.updateFunc + 8680
    frame #37: 0x000000010509b564 zig`link.doTask + 3504
    frame #38: 0x0000000104dcf074 zig`Compilation.performAllTheWorkInner + 18724
    frame #39: 0x0000000104d1249c zig`Compilation.update + 7816
    frame #40: 0x0000000104d311b4 zig`main.updateModule + 52
    frame #41: 0x0000000104d7619c zig`main.buildOutputType + 103680
    frame #42: 0x0000000104cc95ec zig`main + 2680
    frame #43: 0x0000000188b64274 dyld`start + 2840

Expected Behavior

It should print an error explaining the mistake(s) I made in the branch instead of segfaulting before printing an error.

[190n]

Instead of running our whole build system, you can extract this file into the bun-temp repo created following Jarred's instructions and then run zig build obj --prefix build/debug -Dcodegen_path=build/debug/codegen (with Zig 0.14.1) to repro.

build.tgz