Github Some changes to rustdoc fingerprint checking. by ehuss · Pull Request #94...

ehuss commented 13 days ago •

#8640 introduced a check which deletes the doc directory if cargo detects it has stale contents from a different toolchain version. Rustdoc has some shared files (js and css for example) that can get corrupted between versions. Unfortunately that caused some problems with rustbuild which does a few unusual things. Rustbuild will:

• Create the doc directory before running cargo doc and places a .stamp file inside it.
• Creates symlinks of the doc directory so that they can be shared across different target directories (in particular, between rustc and rustdoc).

In order to address these issues, this PR does several things:

• Adds -Z skip-rustdoc-fingerprint to disable the doc clearing behavior.
• Don't delete the doc directory if the rustdoc fingerprint is missing. This is intended to help with the scenario where the user creates a doc directory ahead of time with pre-existing contents before the first build. The downside is that cargo will not be able to protect against switching from pre-1.53 to post-1.53.
• Don't delete the doc directory itself (just its contents). This should help if the user created the doc directory as a symlink to somewhere else.
• Don't delete hidden files in the doc directory. This isn't something that rustdoc creates.

Only the -Z change is needed for rustbuild. The others I figured I'd include just to be on the safe side in case there are other users doing unusual things (and I had already written them thinking they would work for rustbuild). Hopefully the rustbuild .stamp mechanism will be enough protection there.

Fixes #9336