Dispatcher "raise an error on leaked runner" flake

[armanbilge]

5504419

https://cirrus-ci.com/task/5809014697623552?logs=main#L3024

[info] DispatcherSpec
[info] sequential dispatcher should
[info]   await = true
...
[error]     x raise an error on leaked runner
[error]      Expected: java.lang.IllegalStateException. Got nothing (DispatcherSpec.scala:256)

cats-effect/tests/shared/src/test/scala/cats/effect/std/DispatcherSpec.scala

Lines 253 to 259 in 5504419

	"raise an error on leaked runner" in real {
	dispatcher.use(IO.pure(_)) flatMap { runner =>
	IO {
	runner.unsafeRunAndForget(IO(ko)) must throwAn[IllegalStateException]
	}
	}
	}

[armanbilge]

Flaked again.

1bbe7f6

https://cirrus-ci.com/task/4850274011971584?logs=main#L3010

[armanbilge]

By adding replicates to the test in efd0c23 I was able to reproduce more easily. It's not specific to any Dispatcher, just seems generally broken 😕

sbt:cats-effect> testsJVM/testOnly cats.effect.std.DispatcherSpec -- ex "raise an error on leaked runner"
[info] DispatcherSpec
[info] sequential dispatcher should
[info]   await = true
[error]     x raise an error on leaked runner
[error]      Expected: java.lang.IllegalStateException. Got nothing (DispatcherSpec.scala:256)
[info]   await = false
[error]     x raise an error on leaked runner
[error]      Expected: java.lang.IllegalStateException. Got nothing (DispatcherSpec.scala:256)
[info] parallel dispatcher should
[info]   await = true
[error]     x raise an error on leaked runner
[error]      Expected: java.lang.IllegalStateException. Got nothing (DispatcherSpec.scala:256)
[info]   await = false
[error]     x raise an error on leaked runner
[error]      Expected: java.lang.IllegalStateException. Got nothing (DispatcherSpec.scala:256)
[info] Total for specification DispatcherSpec

[durban]

Another example: https://github.com/typelevel/cats-effect/actions/runs/6497507058/job/17646786126#step:22:4783