MacOS default rust install, error with libunwind

[sumeetgadagkar]

I installed rust on MacOS

ProductName: macOS
ProductVersion: 15.1.1
BuildVersion: 24B91

using the following command, choosing the defaults:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

then I tried a simple hello world program

fn main() {
    println!("Hello World!");
}

I build this using :

rustc hello-world.rs

I expected the following output :

Hello World!

However I for the following error :

dyld[29219]: Library not loaded: @rpath/libunwind.1.dylib
  Referenced from: <C4B48CCB-A856-3A54-ADFE-DBED28999910> /Users/sumeet/Documents/projects/scratch/rust-test/hello-world
  Reason: no LC_RPATH's found
Abort trap: 6

I was able to get around it by doing :

install_name_tool -add_rpath /usr/local/lib hello-world

but my question is, shouldn't /usr/local/lib be part of the default rpath?

Meta

rustc --version --verbose:

rustc 1.83.0 (90b35a623 2024-11-26)
binary: rustc
commit-hash: 90b35a6239c3d8bdabc530a6a0816f7ff89a0aaf
commit-date: 2024-11-26
host: aarch64-apple-darwin
release: 1.83.0
LLVM version: 19.1.1

[sumeetgadagkar]

Might be related to #127100

[bjorn3]

shouldn't /usr/local/lib be part of the default rpath?

No, that is not part of macOS.

We should link against the unwinder that is part of macOS (to be precise it is part of libSystem.dylib which all executables link against), not against an unwinder in /usr/local/lib. Did you install libunwind.dylib using homebrew? And why is it trying to link against libunwind.dylib anyway?

What does rustc hello-world.rs --print link-args show?

[sumeetgadagkar]

All libs installed from hombrew go into /opt/homebrew/lib. I am not sure what installed libunwind in /usr/local/lib. When I do fd libunwind.1.dylib / I get :

/usr/local/lib/libunwind.1.dylib
/System/Volumes/Data/usr/local/lib/libunwind.1.dylib

And the output of rustc hello-world.rs --print link-args :

env -u IPHONEOS_DEPLOYMENT_TARGET -u TVOS_DEPLOYMENT_TARGET -u XROS_DEPLOYMENT_TARGET LC_ALL="C" PATH="/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/bin:/Users/sumeet/.cargo/bin:/opt/homebrew/opt/[email protected]/bin:/opt/homebrew/bin:/opt/homebrew/sbin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin" VSLANG="1033" ZERO_AR_DATE="1" "cc" "/var/folders/ww/vkkrl9y91mb3ypvqg59fc8rm0000gn/T/rustc6WSaPu/symbols.o" "hello-world.hello_world.91b974f2db3b334a-cgu.0.rcgu.o" "hello-world.4mligsjdjlmckso3mtp4jdbpa.rcgu.o" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libstd-83616591c03b4bdb.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libpanic_unwind-ebf901b6d23bf634.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libobject-7710b4452bd82af9.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libmemchr-f98cf7c088667f19.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libaddr2line-6392ea87905caffc.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libgimli-25a08af37ed77b0e.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/librustc_demangle-284c364e42397f3c.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libstd_detect-0ca552d44faec676.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libhashbrown-3d585033511079b9.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/librustc_std_workspace_alloc-6619a2e13d28fdc8.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libminiz_oxide-6ed5108eff20a13b.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libadler-4dc30e5b1322c3d7.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libunwind-1abf6f4ec08a1e84.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libcfg_if-189cd29769b1eb60.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/liblibc-b73012c1f7d960db.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/liballoc-60825299673ba243.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/librustc_std_workspace_core-0ffffa7eb0407c16.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libcore-ec2fdc463bb543f6.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libcompiler_builtins-d6d5c321a716d6df.rlib" "-lSystem" "-lc" "-lm" "-arch" "arm64" "-mmacosx-version-min=11.0.0" "-o" "hello-world" "-Wl,-dead_strip" "-nodefaultlibs"

[bjorn3]

What does which cc show? And RUSTC_LOG=rustc_codegen_ssa::back rustc hello-world.rs -Clink-arg=-v? I'm wondering if the linker you have installed decides to add -lunwind to link against libunwind.dylib when it shouldn't.

[sumeetgadagkar]

which cc gives : /usr/bin/cc and RUSTC_LOG=rustc_codegen_ssa::back rustc hello-world.rs -Clink-arg=-v gives :

warning: some trace filter directives would enable traces that are disabled statically
note: `rustc_codegen_ssa::back=trace` would enable the TRACE level for the `rustc_codegen_ssa::back` target
note: the static max level is `info`
help: to enable DEBUG logging, remove the `max_level_info` feature from the `tracing` crate
  INFO rustc_codegen_ssa::back::link preparing Executable to "hello-world"
  INFO rustc_codegen_ssa::back::link env -u IPHONEOS_DEPLOYMENT_TARGET -u TVOS_DEPLOYMENT_TARGET -u XROS_DEPLOYMENT_TARGET LC_ALL="C" PATH="/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/bin:/Users/sumeet/.cargo/bin:/opt/homebrew/opt/[email protected]/bin:/opt/homebrew/bin:/opt/homebrew/sbin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin" VSLANG="1033" ZERO_AR_DATE="1" "cc" "/var/folders/ww/vkkrl9y91mb3ypvqg59fc8rm0000gn/T/rustcvCpzUX/symbols.o" "hello-world.hello_world.91b974f2db3b334a-cgu.0.rcgu.o" "hello-world.4mligsjdjlmckso3mtp4jdbpa.rcgu.o" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libstd-83616591c03b4bdb.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libpanic_unwind-ebf901b6d23bf634.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libobject-7710b4452bd82af9.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libmemchr-f98cf7c088667f19.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libaddr2line-6392ea87905caffc.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libgimli-25a08af37ed77b0e.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/librustc_demangle-284c364e42397f3c.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libstd_detect-0ca552d44faec676.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libhashbrown-3d585033511079b9.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/librustc_std_workspace_alloc-6619a2e13d28fdc8.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libminiz_oxide-6ed5108eff20a13b.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libadler-4dc30e5b1322c3d7.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libunwind-1abf6f4ec08a1e84.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libcfg_if-189cd29769b1eb60.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/liblibc-b73012c1f7d960db.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/liballoc-60825299673ba243.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/librustc_std_workspace_core-0ffffa7eb0407c16.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libcore-ec2fdc463bb543f6.rlib" "/Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libcompiler_builtins-d6d5c321a716d6df.rlib" "-lSystem" "-lc" "-lm" "-arch" "arm64" "-mmacosx-version-min=11.0.0" "-o" "hello-world" "-Wl,-dead_strip" "-nodefaultlibs" "-v"
  INFO rustc_codegen_ssa::back::link linker stderr:
 Apple clang version 16.0.0 (clang-1600.0.26.4)
 Target: arm64-apple-darwin24.1.0
 Thread model: posix
 InstalledDir: /Library/Developer/CommandLineTools/usr/bin
  "/Library/Developer/CommandLineTools/usr/bin/ld" -demangle -lto_library /Library/Developer/CommandLineTools/usr/lib/libLTO.dylib -dynamic -arch arm64 -platform_version macos 11.0.0 15.1 -syslibroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -mllvm -enable-linkonceodr-outlining -o hello-world -L/usr/local/lib /var/folders/ww/vkkrl9y91mb3ypvqg59fc8rm0000gn/T/rustcvCpzUX/symbols.o hello-world.hello_world.91b974f2db3b334a-cgu.0.rcgu.o hello-world.4mligsjdjlmckso3mtp4jdbpa.rcgu.o /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libstd-83616591c03b4bdb.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libpanic_unwind-ebf901b6d23bf634.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libobject-7710b4452bd82af9.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libmemchr-f98cf7c088667f19.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libaddr2line-6392ea87905caffc.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libgimli-25a08af37ed77b0e.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/librustc_demangle-284c364e42397f3c.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libstd_detect-0ca552d44faec676.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libhashbrown-3d585033511079b9.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/librustc_std_workspace_alloc-6619a2e13d28fdc8.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libminiz_oxide-6ed5108eff20a13b.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libadler-4dc30e5b1322c3d7.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libunwind-1abf6f4ec08a1e84.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libcfg_if-189cd29769b1eb60.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/liblibc-b73012c1f7d960db.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/liballoc-60825299673ba243.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/librustc_std_workspace_core-0ffffa7eb0407c16.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libcore-ec2fdc463bb543f6.rlib /Users/sumeet/.rustup/toolchains/stable-aarch64-apple-darwin/lib/rustlib/aarch64-apple-darwin/lib/libcompiler_builtins-d6d5c321a716d6df.rlib -lSystem -lc -lm -dead_strip
 ld: warning: reexported library with install name '@rpath/libunwind.1.dylib' found at '/usr/local/lib/libunwind.1.0.dylib' couldn't be matched with any parent library and will be linked directly
  INFO rustc_codegen_ssa::back::link linker stdout:

I have llvm installed via homebrew. brew info llvm gives :

==> llvm: stable 19.1.6 (bottled), HEAD [keg-only]
Next-gen compiler infrastructure
https://llvm.org/
Installed
/opt/homebrew/Cellar/llvm/19.1.6 (8,107 files, 1.9GB)
  Poured from bottle using the formulae.brew.sh API on 2024-12-22 at 13:20:20
From: https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/l/llvm.rb
License: Apache-2.0 WITH LLVM-exception
==> Dependencies
Build: cmake ✔, ninja ✔, swig ✔
Required: [email protected] ✔, xz ✔, z3 ✔, zstd ✔
==> Options
--HEAD
	Install HEAD version
==> Caveats
CLANG_CONFIG_FILE_SYSTEM_DIR: /opt/homebrew/etc/clang
CLANG_CONFIG_FILE_USER_DIR:   ~/.config/clang

LLD is now provided in a separate formula:
  brew install lld

We plan to build LLVM 20 with `LLVM_ENABLE_EH=OFF`. Please see:
  https://github.com/orgs/Homebrew/discussions/5654

Using `clang`, `clang++`, etc., requires a CLT installation at `/Library/Developer/CommandLineTools`.
If you don't want to install the CLT, you can write appropriate configuration files pointing to your
SDK at ~/.config/clang.

To use the bundled libunwind please use the following LDFLAGS:
  LDFLAGS="-L/opt/homebrew/opt/llvm/lib/unwind -lunwind"

To use the bundled libc++ please use the following LDFLAGS:
  LDFLAGS="-L/opt/homebrew/opt/llvm/lib/c++ -L/opt/homebrew/opt/llvm/lib/unwind -lunwind"

NOTE: You probably want to use the libunwind and libc++ provided by macOS unless you know what you're doing.

llvm is keg-only, which means it was not symlinked into /opt/homebrew,
because macOS already provides this software and installing another version in
parallel can cause all kinds of trouble.

If you need to have llvm first in your PATH, run:
  echo 'export PATH="/opt/homebrew/opt/llvm/bin:$PATH"' >> /Users/sumeet/.bash_profile

For compilers to find llvm you may need to set:
  export LDFLAGS="-L/opt/homebrew/opt/llvm/lib"
  export CPPFLAGS="-I/opt/homebrew/opt/llvm/include"
==> Analytics
install: 70,417 (30 days), 227,991 (90 days), 748,108 (365 days)
install-on-request: 34,611 (30 days), 117,851 (90 days), 373,523 (365 days)
build-error: 417 (30 days)

I have not updated LDFLAGS or PATH to add homebrew installed llvm.

[bjorn3]

For some reason -L/usr/local/lib is getting passed to the linker by clang, which is likely the reason /usr/local/lib/libunwind.dylib gets picked up by the linker. Maybe env | grep LIBRARY_PATH will show the reason why?

[sumeetgadagkar]

env | grep LIBRARY_PATH came up empty. env gives :

SHELL=/opt/homebrew/bin/bash
WINDOWID=4867825680
COLORTERM=truecolor
XPC_FLAGS=0x0
__CFBundleIdentifier=org.alacritty
SSH_AUTH_SOCK=/private/tmp/com.apple.launchd.yxPbsdhBBr/Listeners
HOMEBREW_PREFIX=/opt/homebrew
PWD=/Users/sumeet/Documents/projects/scratch/rust-test
LOGNAME=sumeet
COMMAND_MODE=unix2003
HOME=/Users/sumeet
STARSHIP_SHELL=bash
TMPDIR=/var/folders/ww/vkkrl9y91mb3ypvqg59fc8rm0000gn/T/
BASH_SILENCE_DEPRECATION_WARNING=1
STARSHIP_SESSION_KEY=2167981131404292
ALACRITTY_SOCKET=/var/folders/ww/vkkrl9y91mb3ypvqg59fc8rm0000gn/T/Alacritty-21697.sock
INFOPATH=/opt/homebrew/share/info:
TERM=xterm-256color
USER=sumeet
HOMEBREW_CELLAR=/opt/homebrew/Cellar
SHLVL=1
HOMEBREW_REPOSITORY=/opt/homebrew
XPC_SERVICE_NAME=0
LC_ALL=en_US.UTF-8
PATH=/Users/sumeet/.cargo/bin:/opt/homebrew/opt/[email protected]/bin:/opt/homebrew/bin:/opt/homebrew/sbin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin
ALACRITTY_LOG=/var/folders/ww/vkkrl9y91mb3ypvqg59fc8rm0000gn/T/Alacritty-21697.log
ALACRITTY_WINDOW_ID=4867825680
OLDPWD=/Users/sumeet
__CF_USER_TEXT_ENCODING=0x1F5:0x0:0x0
_=/usr/bin/env

[sumeetgadagkar]

I ran brew doctor and it listed a few dylibs in /usr/local/lib that needed to be removed. libunwind was one of them. After doing so the issue was resolved. Thank you for all your help! Closing this out.