text emitter: use singular form when there was only 1 unmatched diagnostic

[ada4a]

TODO (check if already done)

• Add tests
  • .. but wasn't able to bless them as the test suite seems to hang for some reason
• Add CHANGELOG.md entry
• Bumped minor version and committed lockfiles in case a release is desired

[oli-obk]

hmm I'll have to try the test suite locally, but are you sure it hangs and doesn't just take forever (it rebuilds a lot of things on the first run)

[ada4a]

Thanks for starting CI:)

are you sure it hangs and doesn't just take forever (it rebuilds a lot of things on the first run)

I mean my laptop is admittedly quite slow, but AFAICT it isn't the rebuilding part that fails, just the integration test in particular:

     Running tests/integration.rs (target/debug/deps/integration-a917ca08f79bf777)
tests/integrations/basic/Cargo.toml ⠤
tests/integrations/basic-bin/Cargo.toml ⠤
tests/integrations/basic-fail-mode/Cargo.toml ⠠
tests/integrations/cargo-run/Cargo.toml ⠠
tests/integrations/ui_test_dep_bug/Cargo.toml ⠠
tests/integrations/basic-fail/Cargo.toml ⠠
tests/integrations/dep-fail/Cargo.toml ⠠ 

[ada4a]

Oh, it did move after a while! The thing is that it completely maxed out all the CPUs, which is why I assumed that it got into an infinite loop somewhere

EDIT: Okay, yeah, the following runs are much smoother

[oli-obk]

Yea it rebuilds the crate for each of those tests

[ada4a]

I also got a bunch of seemingly unrelated changes when running cargo test -- -- --bless; I removed them, I think the committed changes should be the correct ones

EDIT: oh no, apparently some unrelated changes did end up sneaking into Cargo.stdout

[oli-obk]

Maybe I need to do a version bump again of the rust version we use, let's see what CI says

[ada4a]

That does sound right -- many of the changes seem to come from improved rustc diagnostics

EDIT: Ahh, right! That's because I have Cargo installed as a free-standing program (so not from rustup), which is why rust-toolchain.toml isn't respected and I end up running the latest stable instead of 1.80.1. Apologies for the confusion

[oli-obk]

Great! Thanks for the fix

[ada4a]

Sorry, I'd realized that my test case doesn't actually test what it was supposed to test -- I wanted to make it emit there were 2 unmatched diagnostics, but for some reason, it emits there was 1 unmatched diagnostic twice instead. Would you happen to know why that would be?.. I'd then open a follow-up PR to fix up the test

[oli-obk]

Hmm I saw the test changes for 1 unmatched diagnostic and forgot to check that there's still a case for 2+

[oli-obk]

Could also bless the output so we only see the missing annotation error

[oli-obk]

Maybe there need to be multiple per line for there to be just one diagnostic informing us about multiple cases

[oli-obk]

Tho I think it maybe best if we had one big diagnostic for all unmatched diagnostics,