loongarch64 musl need enable a static runtime

[wojiushixiaobai]

After some basic testing, it was discovered that the loongarch64-unknown-linux-musl target requires manual configuration to enable the static runtime, similar to the mips64 target as shown here:

• https://github.com/rust-cross/rust-musl-cross/blob/main/Dockerfile#L128

Install Rust target
  info: downloading component 'rust-std' for 'loongarch64-unknown-linux-musl'
  info: installing component 'rust-std' for 'loongarch64-unknown-linux-musl'
🔗 Found bin bindings
📡 Using build options bindings from pyproject.toml
🎯 Found 2 Cargo targets in `Cargo.toml`: foo, hello-world
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.01s
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.01s
💥 maturin failed
  Caused by: Cannot repair wheel, because required library libgcc_s-c0abacde.so.1 could not be located.
Error: The process '/usr/bin/docker' failed with exit code 1
    at ExecState._setResult (/home/runner/work/maturin-action/maturin-action/dist/index.js:1823:25)
    at ExecState.CheckComplete (/home/runner/work/maturin-action/maturin-action/dist/index.js:1[80](https://github.com/loong64/maturin-action/actions/runs/15127990432/job/42523723034#step:8:85)6:18)
    at ChildProcess.<anonymous> (/home/runner/work/maturin-action/maturin-action/dist/index.js:1700:27)
    at ChildProcess.emit (node:events:524:28)
    at maybeClose (node:internal/child_process:1104:16)
    at ChildProcess._handle.onexit (node:internal/child_process:304:5)

• https://github.com/loong64/maturin-action/actions/runs/15127990432/job/42523723034

env:
    RUST_BACKTRACE: '1'
    CARGO_TARGET_LOONGARCH64_UNKNOWN_LINUX_MUSL_RUSTFLAGS: '-C target-feature=+crt-static'

[messense]

rust-musl-cross is for building musl static binaries so it makes sense, but as per PEP musllinux should dynamicially link musl libc, do you know why does it need libgcc_s?

[wojiushixiaobai]

Maybe it is related to:

• Error loading shared library libgcc_s.so.1; Error relocating XXX (musl, Ubuntu) rust-lang/rust#108907
• -crt-static on musl links with libgcc_s rust-lang/rust#82521

[messense]

Is it possible to build a musl libgcc_s.so in our docker image so maturin can bundle it?

[messense]

Maybe just download one from Alpine Linux packages if it's compatible: https://pkgs.alpinelinux.org/package/edge/main/loongarch64/libgcc

[wojiushixiaobai]

I found some discussions, but regardless, I think we can first test and verify the feasibility.

• Link against LLVM libunwind (statically) instead of libgcc_s (dynamically) on Linux targets rust-lang/rust#119504
• x86_64-unknown-linux-musl with -Ctarget-feature=-crt-static links to glibc rust-lang/rust#135244

[wojiushixiaobai]

Disable a static runtime.
The build is successful (no errors), but it crashes during run.

(py3) root@350e0050986a:/opt/uv# env
HOSTNAME=350e0050986a
PWD=/opt/uv
TARGET_AR=loongarch64-unknown-linux-musl-ar
AR_loongarch64_unknown_linux_musl=loongarch64-unknown-linux-musl-ar
CXX_loongarch64_unknown_linux_musl=loongarch64-unknown-linux-musl-g++
CARGO_BUILD_TARGET=loongarch64-unknown-linux-musl
HOME=/root
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.zst=01;31:*.tzst=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.wim=01;31:*.swm=01;31:*.dwm=01;31:*.esd=01;31:*.jpg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.webp=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:
VIRTUAL_ENV=/opt/py3
TARGET_CC=loongarch64-unknown-linux-musl-gcc
LOONGARCH64_UNKNOWN_LINUX_MUSL_OPENSSL_DIR=/usr/loongarch64-unknown-linux-musl/
TARGET_SYSROOT=/usr/loongarch64-unknown-linux-musl/loongarch64-unknown-linux-musl/sysroot/
TARGET_CXX=loongarch64-unknown-linux-musl-g++
CC_loongarch64_unknown_linux_musl=loongarch64-unknown-linux-musl-gcc
TARGET_C_INCLUDE_PATH=/usr/loongarch64-unknown-linux-musl/loongarch64-unknown-linux-musl/sysroot/usr/include/
TERM=xterm
SHLVL=1
VIRTUAL_ENV_PROMPT=(py3) 
PS1=(py3) \[\e]0;\u@\h: \w\a\]${debian_chroot:+($debian_chroot)}\u@\h:\w\$ 
TARGET_RANLIB=loongarch64-unknown-linux-musl-ranlib
TARGET_READELF=loongarch64-unknown-linux-musl-readelf
CARGO_TARGET_LOONGARCH64_UNKNOWN_LINUX_MUSL_LINKER=loongarch64-unknown-linux-musl-gcc
TARGET_CMAKE_TOOLCHAIN_FILE_PATH=/usr/loongarch64-unknown-linux-musl/cmake-toolchain.cmake
PATH=/opt/py3/bin:/root/.cargo/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/loongarch64-unknown-linux-musl/bin
DEBIAN_FRONTEND=noninteractive
OLDPWD=/opt
_=/usr/bin/env

(py3) root@350e0050986a:/opt/uv# find / -name libgcc_s.so.1
/usr/lib32/libgcc_s.so.1
/usr/lib/x86_64-linux-gnu/libgcc_s.so.1
/usr/loongarch64-unknown-linux-musl/loongarch64-unknown-linux-musl/sysroot/lib/libgcc_s.so.1
/usr/loongarch64-unknown-linux-musl/loongarch64-unknown-linux-musl/lib/libgcc_s.so.1

   Compiling uv-build v0.7.6 (/opt/uv/crates/uv-build)
    Finished `minimal-size` profile [optimized] target(s) in 1m 25s
🖨  Copied external shared libraries to package uv_build.libs directory:
    /usr/loongarch64-unknown-linux-musl/loongarch64-unknown-linux-musl/sysroot/lib/libgcc_s.so.1
📦 Built wheel to crates/uv-build/dist/uv_build-0.7.6-py3-none-musllinux_1_2_loongarch64.whl

/opt # uv-build -h
Error loading shared library libgcc_s.so.1: No such file or directory (needed by /usr/local/bin/uv-build)
Error relocating /usr/local/bin/uv-build: _Unwind_FindEnclosingFunction: symbol not found
Error relocating /usr/local/bin/uv-build: _Unwind_Backtrace: symbol not found
Error relocating /usr/local/bin/uv-build: _Unwind_GetRegionStart: symbol not found
Error relocating /usr/local/bin/uv-build: _Unwind_GetTextRelBase: symbol not found
Error relocating /usr/local/bin/uv-build: _Unwind_GetIPInfo: symbol not found
Error relocating /usr/local/bin/uv-build: _Unwind_GetLanguageSpecificData: symbol not found
Error relocating /usr/local/bin/uv-build: _Unwind_GetIP: symbol not found
Error relocating /usr/local/bin/uv-build: _Unwind_GetCFA: symbol not found
Error relocating /usr/local/bin/uv-build: _Unwind_GetDataRelBase: symbol not found
Error relocating /usr/local/bin/uv-build: _Unwind_SetGR: symbol not found
Error relocating /usr/local/bin/uv-build: _Unwind_Resume: symbol not found
Error relocating /usr/local/bin/uv-build: _Unwind_SetIP: symbol not found

After installing the libgcc package, it works normally.
This behaves differently from other architectures.

[wojiushixiaobai]

• https://github.com/PyO3/maturin/blob/main/src/auditwheel
• https://github.com/PyO3/maturin/blob/main/src/auditwheel/policy.rs#L95

# find /usr/loongarch64-unknown-linux-musl/ -name ld-*.so.1
/usr/loongarch64-unknown-linux-musl/loongarch64-unknown-linux-musl/sysroot/lib/ld-musl-loongarch64.so.1

auditwheel show /opt/uv_build-0.7.6-py3-none-musllinux_1_2_loongarch64.whl 

uv_build-0.7.6-py3-none-musllinux_1_2_loongarch64.whl is consistent
with the following platform tag: "linux_loongarch64".

The wheel references external versioned symbols in these
system-provided shared libraries: libgcc_s.so.1 with versions
{'GCC_4.2.0', 'GLIBC_2.0', 'GCC_3.0', 'GCC_3.3'}

The following external shared libraries are required by the wheel:
{
    "libc.musl-loongarch64.so.1": "/lib/ld-musl-loongarch64.so.1",
    "libc.so": "/lib/ld-musl-loongarch64.so.1",
    "libgcc_s.so.1": "/usr/lib/libgcc_s.so.1"
}

In order to achieve the tag platform tag 'musllinux_1_2_loongarch64'
the following shared library dependencies will need to be eliminated:

libc.so, libgcc_s.so.1