proc-macro crate in workspace unexpectently exits

[Javagedes]

Describe the bug
Workspaces with a proc-macro crate fail to execute tests (The failure happens when execution of the test exe begins, but before any test starts) with the following error:

2024-10-28T15:58:05.678629Z  INFO cargo_tarpaulin::process_handling: running D:\a\rust-ci-testing\rust-ci-testing\target\debug\deps\rust_proc_macro-6ef64dc17f0828ce.exe
2024-10-28T15:58:05.678931Z  INFO cargo_tarpaulin::process_handling: Setting LLVM_PROFILE_FILE
2024-10-28T15:58:05.686895Z ERROR cargo_tarpaulin: Test failed during run
Error: "Test failed during run"
Error: Process completed with exit code 1.

I can only reproduce on a github action windows-latest runner (but 100% of the time). It does not happen on ubuntu-latest image (even with the --engine llvm flag) and it does not happen on windows locally. it fails with or without any tests actually in the crate. It fails with engine llvm and --no-dead-code

I tried adding tests to see if that helped any, but it continued to fail. I also tried adding tests as described in #326 but it continues to fail.

I am currently on:
cargo-tarpaulin 0.31.2
1.80.0

To Reproduce
I have set up a repo with a CI job that hits the issue: Javagedes/rust-ci-testing with an example run here: action/Run Tests

Expected behavior
I would expect the test harness to not unexpectedly fail without running any tests.

[xd009642]

Hmm that's super odd, could you add --dump-traces to the tarpaulin flags. Hopefully it's not so long that GHA gives up on printing the logs.

I don't really use windows so this might take me some time to replicate (I need to find a windows machine and setup a dev env or find a friend who can help to get a quicker turnaround)

[nightkr]

I'm seeing something similar on Linux after upgrading to Rust 1.83.0, both in CI (GitHub Actions) and locally (Arch). Rust 1.82.0 seems to work fine.

[xd009642]

oh weird/interesting that's very helpful thanks 👍

[nightkr]

Output from --dump-traces: tarpaulin_20241129173337.json

[nightkr]

Of course, feel free to split this into a separate issue if it seems unrelated.

[jonasbb]

Locally (Rust 1.83, Fedora Linux, amd64) I see these messages right before the test failure. serde_with_macros is a proc-macro crate.

2024-12-02T21:57:21.820615Z  INFO cargo_tarpaulin::process_handling::linux: Launching test
2024-12-02T21:57:21.820661Z  INFO cargo_tarpaulin::process_handling: running /home/jbushart/projects/serde_with/target/debug/deps/serde_with_macros-ae28cd5b53cb79aa
/home/jbushart/projects/serde_with/target/debug/deps/serde_with_macros-ae28cd5b53cb79aa: error while loading shared libraries: libstd-02dc84f49135b6b8.so: cannot open shared object file: No such file or directory
2024-12-02T21:57:23.109267Z ERROR cargo_tarpaulin: Test failed during run
Error: "Test failed during run"

I do not see the link message on GitHub Actions (Source).

test result: ok. 79 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 1.25s

Error: "Test failed during run"
Error: Process completed with exit code 1.

Since this is a linking issue, this change sounds relevant: "The sysroot no longer contains the std dynamic library in its top-level lib/ dir." rust-lang/rust#131188

The issue does not appear with Rust 1.82. The version of tarpaulin (0.31.2 or 0.31.3) does not make a difference.

[xd009642]

Oh one thing that another person with the issue has confirmed is that --exclude <PROC_MACRO_CRATE> also works to solve the issue as a stop gap

[dkaluza]

For me setting dynamic libraries path environment variable manually worked as a workaround:

LD_LIBRARY_PATH="$(rustc --print=target-libdir)" cargo tarpaulin -o html

Note that name of the env variable differs depending on operating system: https://doc.rust-lang.org/cargo/reference/environment-variables.html#dynamic-library-paths

[waltronix]

The issue seems to be related to rust-lang/rust#131188

The searched libstd version is no longer available in sysroot since v1.83