Can't build using musl as a build target.

[iddm]

So I am using github actions to build my crate and when running this step:

      - name: Build static
        uses: stevenleadbeater/rust-musl-builder@master
        with:
            args: /bin/bash -c "cargo build --locked --release --target=x86_64-unknown-linux-musl -v"

It fails with:

Running `rustc --crate-name socket2 --edition=2018 /usr/local/cargo/registry/src/github.com-1ecc6299db9ec823/socket2-0.4.1/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type lib --emit=dep-info,metadata,link -C opt-level=3 -C metadata=aa246bf64056a547 -C extra-filename=-aa246bf64056a547 --out-dir /github/workspace/target/x86_64-unknown-linux-musl/release/deps --target x86_64-unknown-linux-musl -L dependency=/github/workspace/target/x86_64-unknown-linux-musl/release/deps -L dependency=/github/workspace/target/release/deps --extern libc=/github/workspace/target/x86_64-unknown-linux-musl/release/deps/liblibc-d416f6c85e8305e1.rmeta --cap-lints allow`
error: attributes are not yet allowed on `if` expressions
   --> /usr/local/cargo/registry/src/github.com-1ecc6299db9ec823/socket2-0.4.1/src/sys/unix.rs:878:5
    |
878 |     #[cfg(not(any(target_os = "haiku", target_os = "openbsd")))]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0658]: `match` is not allowed in a `const fn`
   --> /usr/local/cargo/registry/src/github.com-1ecc6299db9ec823/socket2-0.4.1/src/lib.rs:156:9
    |
156 | /         match address {
157 | |             SocketAddr::V4(_) => Domain::IPV4,
158 | |             SocketAddr::V6(_) => Domain::IPV6,
159 | |         }
    | |_________^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/49146

error[E0599]: no associated item named `MAX` found for type `i32` in the current scope
   --> /usr/local/cargo/registry/src/github.com-1ecc6299db9ec823/socket2-0.4.1/src/sys/unix.rs:763:46
    |
763 |     msg.msg_iovlen = min(bufs.len(), IovLen::MAX as usize) as IovLen;
    |                                              ^^^ associated item not found in `i32`

error[E0599]: no associated item named `MAX` found for type `i32` in the current scope
   --> /usr/local/cargo/registry/src/github.com-1ecc6299db9ec823/socket2-0.4.1/src/sys/unix.rs:823:46
    |
823 |     msg.msg_iovlen = min(bufs.len(), IovLen::MAX as usize) as IovLen;
    |                                              ^^^ associated item not found in `i32`

error: aborting due to 4 previous errors

Some errors have detailed explanations: E0599, E0658.
For more information about an error, try `rustc --explain E0599`.
error: could not compile `socket2`.

What could be wrong and how to fix it?

[Thomasdezeeuw]

If you read the error it says error[E0658]: 'match' is not allowed in a 'const fn'. This is likely because your compiler is to old, as per the readme the minimum Rustc version for socket2 is 1.46. Have you tried updating your Rust version?

[Thomasdezeeuw]

@vityafx any luck updating your Rustc toolchain?

[iddm]

I guess I can't directly do anything with it as I just rely on the toolchain provided by a third-party github action. Thanks for confirming it is a compiler issue though.