Bad call to rustdoc when cargo test --package feature when using features

[TeXitoi]

TLDR: this (almost) minimal project doesn't work: https://github.com/TeXitoi/cargo_bug_feature_package

When using features, and calling cargo test --package feature, --cfg arguments are bad when calling rustdoc.

[TeXitoi]

Maybe a duplicate of #2539

[alexcrichton]

Right now --cfg flags are passed here to rustdoc which originates from this field which are all filled in here.

The bug here is that we're passing root_pkg to the calculations here, which doesn't work with the --package flag where we're actually testing something other than the root crate. I think this may be the same issue as #2539 because we attempt to pass build script cfg values, but that would require #2539 specifically being related to the -p flag which it currently doesn't mention.

I think we'll want to tweak this logic and perhaps just update Compilation to not only store the cfg values for the root package, but rather the entire crate graph. That way later on we can just look up the relevant piece in the hash table in Compilation instead of always picking the one cfgs value.

I'm going to tag this E-easy as I think it shouldn't be too hard to tackle, but if anyone works on this and needs some help feel free to ping me!

[jhbabon]

Hi @alexcrichton, I can take a look at this if no one has done it yet. (yes, I'm chasing E-easy tags in this project 😆 )

[alexcrichton]

@jhbabon sure! Let me know if you need any pointers!

[jhbabon]

Hi! Sorry for the delay on this. This is the fix I managed to do: #3242