mdbook@0.4.40 ignores rust-toolchain when running rustdoc

[ma2bd]

Problem

mdbook@0.4.40 ignores rust-toolchain when running rustdoc.

This is problematic when running mdbook test -L PATH where PATH contains compiled crates -- likely compiled in a way that doesn't ignore rust-toolchain.

mdbook@0.4.37 is still fine.

Steps

Let me know if you need actual repro steps. I used our own repository. See the CI runs on the commits of linera-io/linera-documentation#171

Possible Solution(s)

No response

Notes

No response

Version

[ehuss]

Hm, yea, it looks like this changed as a result of #2259 which changed it so that rustdoc's current directory is inside the temp folder in order to generate better path displays. I'm not entirely sure how to fix that. Unfortunately it doesn't look like rustup provides a rustup run that will use the current directory's override.

One option might be some kind of path remapping, which I'm uncertain if that is implemented yet (rust-lang/cargo#9887).