Possible regression causing linking of proc_macro

[snowp]

We updated rules_rust from 0.4.0 to 28ac6b1 and ran into an issue where proc_macro is now statically linked into a test binary, causing

/home/runner/.cache/bazel/_bazel_runner/374864cd5aeb008ef6a614637fda772e/sandbox/linux-sandbox/630/execroot/__main__/bazel-out/k8-fastbuild/bin/src/wrapper/buffer_test.runfiles/__main__/src/wrapper/_buffer_test: error while loading shared libraries: libstd-05b39ac0cb4c5688.so: cannot open shared object file: No such file or directory

21eed19...28ac6b1

I made sure that this was not coming from the Rust version upgrade (tried bad sha + 1.60).

I don't have a simple reproducer, though I suspect it's coming from our usage of cxx, though we also make use of other proc_macro libraries such as tokio, thiserror, prost, etc.

[scentini]

I managed to create a simple repro. This is not related to proc_macros; the culprit is #1333 and @krasimirgg and I are discussing the best way forward.

[scentini]

@snowp could you check whether #1394 solves the problem for you?

[snowp]

Running against that branch I get

dyld[52718]: Library not loaded: @rpath/libstd-0dd069df8d91d43f.dylib
  Referenced from: /private/var/tmp/_bazel_snowp/c1591b76b8a2fcd15b6ff3cd34fdd7da/execroot/__main__/bazel-out/darwin_arm64-dbg/bin/src/logger/logger_test
  Reason: tried: '/usr/local/lib/libstd-0dd069df8d91d43f.dylib' (no such file), '/usr/lib/libstd-0dd069df8d91d43f.dylib' (no such file)

for a lot (not all) Rust targets when I apply repository_override to our project

[scentini]

Thanks! That's the same error, just on macos this time, which is a reminder that we should apply the solution to all platforms.

[snowp]

Tried this on Linux and there it seems to be no issues when running the branch, so sounds like this is the right fix and just needs to also be done for macos :)

[Reflejo]

@scentini Were you able to make any progress with this issue? Thanks!

[scentini]

Sorry for the delay; I managed to get CI green in the unpolished (and incorrectly named) #1411. I want to try one more approach before I mark it ready for review. The PR will most likely be ready on Monday, as I'm going to be OOO for the next few days.

[UebelAndre]

@scentini hey, any updates here?

[scentini]

Hey folks, I have #1500 up for review.