Failure to build static musl package with aws-lc-sys dependencies

[TristanCacqueray]

Describe the bug

Building a static command with aws-lc-sys fails with the following error: cannot find -lc: No such file or directory

Reproduction
In the examples/cross-musl/Cargo.toml, add:

[dependencies]
aws-lc-sys = "0.28.2"

Then run the following commands:

$ cd examples/cross-musl
$ cargo build
...
$ nix build
error: builder for '/nix/store/rblk1rwhp0s0789hry56c3nm9qmx5vk8-cross-musl-deps-0.1.0.drv' failed with exit code 101;
       last 25 log lines:
       >   RUSTC_WRAPPER = None
       >   cargo:rerun-if-env-changed=CC_ENABLE_DEBUG_OUTPUT
       >   cargo:rerun-if-env-changed=CRATE_CC_NO_DEFAULTS
       >   CRATE_CC_NO_DEFAULTS = None
       >   DEBUG = Some(false)
       >   CARGO_CFG_TARGET_FEATURE = Some(crt-static,fxsr,sse,sse2)
       >   cargo:rerun-if-env-changed=CFLAGS
       >   CFLAGS = None
       >   cargo:rerun-if-env-changed=TARGET_CFLAGS
       >   TARGET_CFLAGS = None
       >   cargo:rerun-if-env-changed=CFLAGS_x86_64_unknown_linux_musl
       >   CFLAGS_x86_64_unknown_linux_musl = None
       >   cargo:rerun-if-env-changed=CFLAGS_x86_64-unknown-linux-musl
       >   CFLAGS_x86_64-unknown-linux-musl = None
       >   CARGO_ENCODED_RUSTFLAGS = Some(-Ctarget-feature=+crt-static)
       >
       >   --- stderr
       >
       >   thread 'main' panicked at /nix/store/s5ssq2ricm247rwvf8jy8dk170ivxham-vendor-cargo-deps/c19b7c6f923b580ac259164a89f2577984ad5ab09ee9d583b888f934adbbe8d0/aws-lc-sys-0.28.2/builder/cc_builder.rs:476:9:
       >   COMPILER: gccARGS: ["-O3", "-ffunction-sections", "-fdata-sections", "-fPIC", "-m64", "-static", "-Wall", "-Wextra", "/nix/store/diicfd1kkmb1jdxlybxwwsg7d07fcg09-cargo-package-aws-lc-sys-0.28.2/aws-lc/tests/compiler_features_tests/memcmp_invalid_stripped_check.c", "-Wno-unused-parameter", "-o", "/build/source/target/x86_64-unknown-linux-musl/release/build/aws-lc-sys-c336602b344073e3/out/memcmp_invalid_stripped_check"]EXECUTED: trueERROR: /nix/store/hzw38c3f7s0w200cgk9645z53al7k8lw-binutils-2.44/bin/ld: cannot find -lc: No such file or directory
       >   /nix/store/hzw38c3f7s0w200cgk9645z53al7k8lw-binutils-2.44/bin/ld: have you installed the static version of the c library ?
       >   collect2: error: ld returned 1 exit status
       >   OUTPUT: Failed to compile memcmp_invalid_stripped_check
       >
       >   note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
       For full logs, run:
         nix log /nix/store/rblk1rwhp0s0789hry56c3nm9qmx5vk8-cross-musl-deps-0.1.0.drv
error: 1 dependencies of derivation '/nix/store/m7rp309xyxh7q6h4njql1vgrfbi5psr6-cross-musl-0.1.0.drv' failed to build

[TristanCacqueray]

This dependency is required by default for rustls, though it can be disabled and replaced by the ring feature.

[ipetkov]

I don't know enough about aws-lc's internals to guess what the issue might be. Does aws-lc support linking against musl? Does it support statically linked libc at all?

Seems like the build is failing due to aws-lc-sys's own build scripts running in an error so this seems to me like a configuration issue with aws-lc-sys specifically

[TristanCacqueray]

According to https://crates.io/crates/aws-lc-sys it does support musl, and passing AWS_LC_SYS_STATIC=1 to the environment doesn't seem to work either as described in https://github.com/aws/aws-lc-rs/blob/main/book/src/resources.md .