Patch section in a separate file

[wyfo]

Problem

I would like to use patch section to do local development, patching a dependency to use a path. However I don't want to pollute Cargo.toml with local/temporary stuff, because Cargo.toml is versioned.

Proposed Solution

Allow for a new file, named Cargo-patch.toml (or whatever name better suited). When the file is present, its content is added to the patch section of Cargo.toml, overriding items present in both files.

This feature could be turned off (with an environment variable for example) to use unpatched Cargo.toml with tools like pre-commit.

Notes

No response

[ehuss]

Patches can also be specified in a config file. Does that work for you?

[wyfo]

Oh indeed, it's perfect. Sorry for the noise ...

[wyfo]

By the way, maybe the documentation part about Overriding Dependencies is a little bit out of date, because .cargo/config.toml is only mentioned for paths overrides.
(In my case, I wanted to patch git dependencies, so paths overrides would not have worked)

Should I open a new issue about documentation update?

[ehuss]

Nah, I just opened a quick PR at #10836 to include it in the docs. Thanks for the suggestion! I completely missed that we didn't update that chapter. (Config support was just recently added.)