`cargo test --doc` does not test examples

[mkroman]

When running cargo doc --test in a project folder, cargo does not test documentation examples, it only builds the project and exits.

This is when running cargo from nightly.

mk@maero ~/Projects/SoundCloud % cargo test --doc
mk@maero ~/Projects/SoundCloud % 

[mkroman]

I've submitted a pull request. #2685

[huonw]

Fixed by #2685.

[dianpopa]

Hi,

I am able to replicate this problem with rustdoc 1.27.2 (58cc626de 2018-07-18)
and rustc 1.27.2 (58cc626de 2018-07-18). Running cargo test --doc exits without running documentation examples even though the folders that I am trying to run the command for are library crate-types. Any suggestions?

[maddiemort]

+1 on 1.27.0 and 1.27.2.

Edit: It works on 1.28.0-beta (cb019b621 2018-07-05) and 1.29.0-nightly (af9e40c26 2018-07-05), but I need to pass the --doc flag. Just running cargo test doesn't run doc tests. I seem to remember that cargo test used to run doc tests as well... is this an intentional change?

[ehuss]

@dianpopa Can you post an example package that demonstrates the problem?

@sorenmortensen cargo test should run the doc tests. Is cargo not even printing Doc-tests my-package? Does it happen with a simple package with just a library?

[maddiemort]

@ehuss That's correct, it doesn't even print Doc-tests foo. I did just create a simple library package, though, and haven't been able to reproduce it yet. Will keep trying.

Edit: even when I force it to run the doc tests by running cargo +nightly test --doc, it seems not to be able to find the crate, even when I add an extern crate foo; declaration.

[maddiemort]

I believe I've found the culprit. It's because I've set the crate-type in Cargo.toml. I'm using crate-type = ["staticlib"], but I can reproduce this also with "dylib". Should I open a new issue, as this seems to be different?

Here is a minimal example that reproduces the problem.

[ehuss]

@sorenmortensen Thanks for the info. Only rlibs support doctests. It was an unintentional change to allow you to even try with test --doc. I'll take care of that, thanks!

[dwijnand]

@ehuss' is taking care of it in #5801 :)

[dianpopa]

I discovered what was the problem for me. If I remove x86_64-unknown-linux-musl target from .cargo/config I am able to see the Doc-tests being run. I am compiling on an x86 machine. If I keep the musl target and I specifically run cargo test like cargo test --target x86_64-unknown-linux-gnu the Doc-tests are successfully run. I am guessing I stumbled upon #4471 which seems to be the expected behavior. However, to me this is not exactly cross-compilation as I am on an x86 host and trying to obtain a musl enabled binary for the same type of architecture (i.e. x86). What is your opinion on this?

[ehuss]

@dianpopa I suggest you add your use case on rust-lang/rust#44404. Unfortunately I suspect it's not easy to fix, but collecting feedback might help.