Accpet `OsStr` instead of `str` for flags

[NobodyXu]

Fixed #1018

[sagudev]

Just note that this is a breaking change: https://github.com/servo/servo/actions/runs/9672905431/job/26686002372?pr=32616#step:12:441

[NobodyXu]

Oops looks like cargo-semver-check missed this one cc @obi1kenobi

678 |             build.flag(&confdefs_path.to_string_lossy());
    |                   ----  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `std::convert::AsRef<std::ffi::OsStr>` is not implemented for `std::borrow::Cow<'_, str>`, which is required by `&std::borrow::Cow<'_, str>: std::convert::AsRef<std::ffi::OsStr>`
    |                   |

looks like we would have to revert the change to the interface and add a set of new interface to accept OsStr

[NobodyXu]

@sagudev It is unfortunate that AsRef does not work for Cow<', str>, however looking at the log, it seems that they are converting an OsStr to Cow<', str> to workaround a past limiation of our interface.

maybe the best way forward is to pass the OsStr directly?

[sagudev]

Yes, indeed. I just wanted to warn that this is a breaking change, although trivial to fix on our side, there might be more crates affected by this.

[NobodyXu]

Thank you, now that we have released 1.0.100, I'm not sure if we should yank and then revert its interface, that could break people on new releases.

On the other hand, most people are probably using old version and has yet update, so maybe we could still yank and revert?

[thomcc]

It's probably worth yanking rather than breaking semver if we have a way to avoid breaking semver.

[thomcc]

Eh, At this point we've probably missed the boat for this to be a good candidate for yanking. I may change my mind if more reports of bustage come in though.

[obi1kenobi]

Oops looks like cargo-semver-check missed this one cc @obi1kenobi

Yup, it can't currently check anything related to changes in types: https://predr.ag/blog/four-challenges-cargo-semver-checks-has-yet-to-tackle/#surprising-limitation-no-checking-of-types

It's tied to the next point in that blog post: a lack of sustainable project funding. I'd love to build type-aware checks, but that requires being able to pay my rent with cargo-semver-checks and we are nowhere close to that right now 😢 I have many individuals sponsoring me on GitHub, and I love them all for it. But what would really move the needle are recurring $100-$500/month company sponsorships, and I haven't been able to get any of those so far — so rent has been coming out of my savings for many months now.

For any folks negatively affected by this issue, please remember:

• cargo-semver-checks can be updated to catch it in the future.
• It's up to you to help make that happen. Please get your employer to sponsor me so I can build it!

Companies, I'd love to put your logo on the cargo-semver-checks README, and I'll tell everyone you're sponsoring me. So dig into your marketing budget and send some love my way!