build fails with "error: Rust build failed; unable to find any build artifacts"

[Krenodeno]

Hi,

I get an error "error: Rust build failed; unable to find any build artifacts" which originated from setuptools-rust https://github.com/PyO3/setuptools-rust/blob/v1.5.1/setuptools_rust/build.py#L284 even if rustc/cargo show no error ("Finished release [optimized] target(s) in 38.90s").

The rust lib build fine, but for any reason, setuptools-rust seems to not find artifacts.

My rust project is a single lib.rs file, compiled with cargo 1.63, setuptools-rust is v1.5.1 and pip is v22.2.1.

---

I tried trying running the rustc line outputed while building with cargo build -v, which output is the following:

rustc --crate-name mylib --edition=2018 src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type dylib --emit=dep-info,link -C embed-bitcode=no -C debuginfo=2 --cfg 'feature="default"' --cfg 'feature="python3"' -C metadata=a67764a0478247b2 --out-dir /home/me/mylib/target/debug/deps -C incremental=/home/me/mylib/target/debug/incremental -L dependency=/home/me/mylib/target/debug/deps --extern cpython=/home/me/mylib/target/debug/deps/libcpython-595113d75631677a.rlib --extern image=/home/me/mylib/target/debug/deps/libimage-3f31a25a1b7e2be8.rlib

{"artifact":"/home/me/mylib/target/debug/deps/watermarkrs.d","emit":"dep-info"}
{"artifact":"/home/me/mylib/target/debug/deps/libwatermarkrs.so","emit":"link"}

Looking at https://github.com/PyO3/setuptools-rust/blob/v1.5.1/setuptools_rust/build.py#L691 could it be that the json output of rustc have changed, then the parsing doesn't work ?

[davidhewitt]

Thanks for reporting. Can you share a minimal repro of your project configuration and your build process which shows the error? The cargo output has not changed and is handled correctly, so the cause is likely in your project configuration.

[Krenodeno]

Okay, I made this minimal example based on the actual project architecture and configuration: https://github.com/Krenodeno/python-rust-reprod

I reproduce the error doing the following:

# python -m venv __env__
# source __env__/bin/activate
# pip install .

Still I don't understand because a month or two back, it worked fine.

I forgot to mentions we use CPython bindings, maybe that's the cause ?

[davidhewitt]

Thanks, I will do my best to debug this in the next few days.

[captainGeech42]

+1, I'm experiencing what is likely the same underlying issue trying to build googleprojectzero/weggli. The rust code builds fine.

$ cargo -V
cargo 1.60.0 (d1fd9fe 2022-03-01)

$ python -V
Python 3.10.7

$ pip freeze | grep setuptools-rust
setuptools-rust==1.5.1

[captainGeech42]

I was able to successfully build by changing kind="cdylib" to kind="dylib" here. Not sure on the ramifications of this, but it worked for this specific build (host OS is Linux fwiw).

The relevant artifact output from Cargo is:

{"reason":"compiler-artifact","package_id":"weggli 0.2.4 (path+file:///home/geech/sec/weggli)","manifest_path":"/home/geech/sec/weggli/Cargo.toml","target":{"kind":["rlib","dylib"],"crate_types":["rlib","dylib"],"name":"weggli","src_path":"/home/geech/sec/weggli/src/lib.rs","edition":"2018","doc":true,"doctest":true,"test":true},"profile":{"opt_level":"3","debuginfo":null,"debug_assertions":false,"overflow_checks":false,"test":false},"features":["pyo3","python"],"filenames":["/home/geech/sec/weggli/target/release/libweggli.rlib","/home/geech/sec/weggli/target/release/libweggli.so"],"executable":null,"fresh":true}

[davidhewitt]

#290 should fix this, I'll try to put out a release within a few days.