Fix E0449

[alexispurslane]

A fix for issue #35924.

[rust-highfive]

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[eddyb]

LGTM. Please squash all your commits first.

[alexispurslane]

Okay, squashed!

[eddyb]

Just realized this should have a test. r? @jonathandturner

[alexispurslane]

@jonathandturner I'm not familiar with the testing setup of Rust, so could you explain to me how to add a test to this? It looks like there already is a compile-fail test for this, but I don't know how to update it to this change. It passes the test, but the test is not very specific.

[sophiajt]

@ChristopherDumas - I wrote a blog post to help with this. Specifically, check out the Extra Credit section of the blog post. It explains that there are quirks in the unit testing tool where it won't test labels until you put in your first NOTE test.

[alexispurslane]

Thank you, I'll check that out.

[bors]

☔ The latest upstream changes (presumably #36761) made this pull request unmergeable. Please resolve the merge conflicts.

[sophiajt]

We landed some fixes to E0449 recently, which I think fix the issue. If there are additional changes that need to be made, you can rebase and send us a new PR.

[alexcrichton]

Closing due to inactivity, but feel free to resubmit with a rebase!