"Error loading shared library libgcc_s.so.1" on Chimera Linux systems (musl+libunwind instead of libgcc_s)

Verification

• I searched for recent similar issues at https://github.com/rust-lang/rustup/issues?q=is%3Aissue and found no duplicates.
• I am on the latest version of Rustup according to https://github.com/rust-lang/rustup/tags and am still able to reproduce my issue.

Problem

Rustup pulls an unusable toolchain on Linux systems using musl libc (such as Chimera Linux).

sattelite% cargo --version
Error loading shared library libgcc_s.so.1: No such file or directory (needed by /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo)
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_Resume: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_GetIPInfo: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_GetDataRelBase: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_GetRegionStart: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_SetGR: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_FindEnclosingFunction: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_GetTextRelBase: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_DeleteException: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_RaiseException: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_GetIP: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_Backtrace: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_GetCFA: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_GetLanguageSpecificData: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/bin/cargo: _Unwind_SetIP: symbol not found
sattelite% rustc --version
Error loading shared library libgcc_s.so.1: No such file or directory (needed by /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so)
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_Resume: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_Resume_or_Rethrow: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_GetRegionStart: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_FindEnclosingFunction: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_GetTextRelBase: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_RaiseException: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_Backtrace: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_SetIP: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_DeleteException: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_GetIP: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_GetIPInfo: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_GetDataRelBase: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_SetGR: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_GetCFA: symbol not found
Error relocating /home/ionutc/.rustup/toolchains/stable-x86_64-unknown-linux-musl/lib/librustc_driver-c37d498bdccbcd4f.so: _Unwind_GetLanguageSpecificData: symbol not found

More info:
Musl version: 1.2.5_git20240705-r12
Gcompat version: 1.1.0-r2
Kernel version: 6.18.2-r0

Steps

1. Use curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh to install rustup, choose the default settings
2. Run cargo --version or rustc --version

Possible Solution(s)

No response

Notes

No response

Rustup version

rustup 1.28.2 (2025-04-28)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `(error reading rustc version)`

Installed toolchains

Default host: x86_64-unknown-linux-musl
rustup home:  /home/ionutc/.rustup

installed toolchains
--------------------
stable-x86_64-unknown-linux-musl (active, default)

active toolchain
----------------
name: stable-x86_64-unknown-linux-musl
active because: it's the default toolchain
installed targets:
  x86_64-unknown-linux-musl

OS version

Linux sattelite 6.18.2-0-generic rust-lang/rustup#1 SMP PREEMPT_DYNAMIC Fri Dec 19 19:13:39 UTC 2025 x86_64
-----
NAME="Chimera"
ID="chimera"
PRETTY_NAME="Chimera Linux"
HOME_URL="https://chimera-linux.org"
DOCUMENTATION_URL="https://chimera-linux.org/docs"
LOGO="chimera-logo"
ANSI_COLOR="0;38;2;214;79;93"

The report names no source files or tests. Start by reproducing the installation and running cargo --version and rustc --version on Chimera Linux, then trace how the x86_64-unknown-linux-musl toolchain is selected or built. Done means the default stable musl toolchain runs both commands without the reported libgcc_s.so.1 and _Unwind errors.