Custom name in [lib] in Cargo.toml causes cargo-semver-checks to be unable to find rustdoc json

[Phantomical]

Steps to reproduce the bug with the above code

This isn't quite a minimal example but it should be reproducible enough.

git clone https://github.com/phantomical/perf-event
cd perf-event
git checkout 47dc882dbfb44b86584540a6e4f2815caaf72c10
sed -i -e 's/version = "5.0.0"/version = "5.0.1"/' perf-event-open-sys/Cargo.toml
cargo semver-checks check-release -p perf-event-open-sys2

Actual Behaviour

cargo-semver-checks exits with the following error:

Error: Could not find expected rustdoc output for `perf-event-open-sys2`: /home/swlynch/projects/tmp/perf-event/target/semver-checks/local-perf_event_open_sys2-5_0_1/target/semver-checks/target/doc/perf_event_open_sys2.json

Expected Behaviour

It should run and check the code as expected.

Generated System Information

Software version

cargo-semver-checks 0.19.0

Operating system

Linux 5.10.0-19-amd64

Command-line

/home/swlynch/.cargo/bin/cargo-semver-checks semver-checks --bugreport 

cargo version

> cargo -V 
cargo 1.70.0-nightly (0e474cfd7 2023-03-31)

Compile time information

• Profile: release
• Target triple: x86_64-unknown-linux-gnu
• Family: unix
• OS: linux
• Architecture: x86_64
• Pointer width: 64
• Endian: little
• CPU features: fxsr,sse,sse2
• Host: x86_64-unknown-linux-gnu

Build Configuration

No response

Additional Context

Putting

[lib]
name = "perf_event_open_sys"

in Cargo.toml causes the emitted json file to be called perf_event_open_sys.json instead of the perf_event_open_sys2.json that cargo-semver-checks is expecting.

[obi1kenobi]

Thanks for the report, and sorry for the inconvenience!

Something quite interesting is going on here, because we've seen this issue before and we've added a test case specifically for it: https://github.com/obi1kenobi/cargo-semver-checks/blob/main/test_rustdoc/renamed_lib/Cargo.toml

I'll have a look shortly.

[obi1kenobi]

I think I've gotten to the bottom of the problem and I have a prototype of the fix that should eliminate problems like this once and for all. Thanks to the kind folks who work on rustdoc, I have a way to replace the hit-or-miss heuristic we were using to find the rustdoc JSON file with something much better.

The fix will be in the next release at the beginning of next week, together with the massive overall speedup of the tool I wrote about a few months ago: https://predr.ag/blog/speeding-up-rust-semver-checking-by-over-2000x/

If you need it more urgently than that, I can try (though unfortunately not commit to) to make a patch release tomorrow morning as well. Let me know!

[Phantomical]

That's awesome! Thank you! No rush on the release. It's not that urgent for me and ultimately I can still make it work for now by manually renaming the files :)

[obi1kenobi]

This was a bit of a marathon issue, but now it's sorted out and the project is better off for it :)

Thanks again for the bug report and quality repro!