Add rust+cargo to musl toolchain

[nikeee]

See #227
See nodejs/docker-node#2486

This probably affects all architectures that are built here.

The only one that is used in the official docker images seems to be x64:
nodejs/docker-node@6027bae

Merging this would prevent the new docker images from being blocked. We probably can fix the cross-compilation later.

[sxa]

Merging this would prevent the new docker images from being blocked. We probably can fix the cross-compilation later.

Noting that the presence of rust will likely cause the the arm builds to fail. A similar solution to nodejs/build#4316 may be all that's required but it would need someone to verify it.

Perhaps @mollux would like to take a look at this?

[nikeee]

Noting that the presence of rust will likely cause the the arm builds to fail.

This PR only touches x64+musl. For arm, the docker image doesn't pull in a binary from unofficial-builds for some reason, but uses a multi-stage-build to build them from source (see: nodejs/docker-node#2488). There the docker image seems to be built on arm64 (or being emulated To arm64) because there don't seem to be any cross-compilations going on.

Not sure if there would be a better solution.

[sxa]

Noting that the presence of rust will likely cause the the arm builds to fail.

This PR only touches x64+musl. For arm, the docker image doesn't pull in a binary from unofficial-builds for some reason, but uses a multi-stage-build to build them from source (see: nodejs/docker-node#2488). There the docker image seems to be built on arm64 (or being emulated To arm64) because there don't seem to be any cross-compilations going on.

Not sure if there would be a better solution.

Correct but the standalone unofficial-build for Alpine/arm64 (not the one that goes into the docker image at present) will likely be affected if we put this in as it would install the x64 version of rust which I expect to fail as per the build issue I mentioned above which was a problem for cross-compiled macos builds.

[nikeee]

Maybe I'm getting this wrong, but i thought musl-arm is built solely from https://github.com/nodejs/unofficial-builds/blob/main/recipes/arm64-musl and not this one. At least that is where some cross-compilation is set up. If this PR breaks the arm build, then we'd probably do it somehow different like you mentioned.

[sxa]

Yeah you're right - my bad (I wish that directory was explicitly musl-x64!). Have you tested these changes to confirm that it definitely builds ok on Alpine/x64?

[nikeee]

I ran ./bin/local_build.sh -r musl -v v26.0.0. After applying the patch, ./configure doesn't print out the two warnings regarding cargo/rust any more. cargo is also invoked, as it prints out some rust-compiler output. Haven't been able to finish an entire build yet, because I ran out of ram before finishing.
It's basically the same change as in nodejs/docker-node#2488 (but for x64 instead of arm) and I was able to confirm that it worked.

My local build is still running and I'll reach back when it finishes.

[sxa]

Just a note on this - adjusting the dockerfile to Alpine 3.23 may cause problems on the Alpine 3.22 image so we'll want to verify that too. FYI @MikeMcC399
It might be better to drop this to 3.22 for now.

[nikeee]

Good point. Done in 67f2cd8

Update: Build went through. Tested it:

[sxa]

Thanks. I think I'm happy to merge this now :-)
If it causes a problem we can adjust later, but this should unblock the container production for Node 26.1.0

[sxa]

LGTM