Fix #4482 and #9449: set Fossil ignore and clean settings locally

[PaulDance]

This aims to close #4482 and close #9449.

Context: currently, the Fossil extension for cargo new would call fossil settings [...] in order to configure the created repository to ignore and allow cleaning the target build directory. However, as #9449 shows, it is ran from the CWD, which is probably outside of the repo, therefore it modifies global settings instead of local ones. This PR fixes that by writing the settings to local versioned files as the issue recommends.

Furthermore, as #9449 notes, configuring the repository's ignore settings only in util::vcs::FossilRepo::init means it is not done when the repository is not new and makes it harder to maintain equivalent support for VCS ignore system implementations. It also completely ignores the --lib CLI option which adds Cargo.lock to the ignore list for Git and Mercurial.

Therefore, the following modifications have been performed, using the Fossil documentation as a reference for the ignore syntax:

• All settings logic has been removed from FossilRepo::init.
• ops::cargo_new::IgnoreList::push now requires a third argument for Fossil-specific glob syntax that is stored in a new fossil_ignore field.
• IgnoreList::format_new uses the fossil_ignore field when needed just like any other VCS.
• IgnoreList::format_existing handles Fossil separately for a few operations as its glob syntax does not support comments, so any lines starting with # cannot be included: the configurations can only be merged here.
• write_ignore_file has been modified a bit as well to enable writing to two files for Fossil specifically in order to keep supporting its cleaning feature. The return type of the function is now CargoResult<()> instead CargoResult<String>: it makes the implementation easier and as the return value was actually not used, I figured it would be okay to do so, plus that return value would not make too much sense anymore for Fossil because of the two possibly different file contents.
• mk has been updated to provide the correct ignore glob to IgnoreList::push for Fossil.

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @Eh2406 (or someone else) soon.

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[PaulDance]

@Eh2406 The workflow seems to have failed on a weird APT error when installing build requisites. Would it be possible to restart the tests or should I fake a change in order to trigger that manually?

[ehuss]

I just restarted them.

[PaulDance]

@ehuss Thanks! Oh, by the way, I noticed a small warning in the CI logs:

warning: use of deprecated associated function `url::Url::into_string`: use Into<String>
   --> src/registry.rs:183:26
    |
183 |                 dl_url().into_string(),
    |                          ^^^^^^^^^^^
    |
    = note: `#[warn(deprecated)]` on by default

for cargo-test-support. It should simply be because it is not reported when building from the parent package. I thought something as small as this would not warrant a dedicated issue, so should I open a PR for this or do you think it would be faster for a team member to do so?

[ehuss]

Thanks! The code is starting to get a little tangled, but I think it's fine for now. If more files or vcs systems are added in the future, we may want to consider abstracting and simplifying it somehow, though I'm not sure what that would look like.

@bors r+

[bors]

📌 Commit 6801c49 has been approved by ehuss

[bors]

⌛ Testing commit 6801c49 with merge 5c45513...

[ehuss]

should I open a PR

Please go ahead!

[PaulDance]

Alright, cool, thank you very much!

[bors]

☀️ Test successful - checks-actions
Approved by: ehuss
Pushing 5c45513 to master...