The source channel is not cancelled when cancelling the result of `produce(onCompletion = consumes())`

The following test hangs:

@Test
fun testCancelProduce() = runTest {
    val source = Channel<Int>()

    val produced = produce<Int>(Unconfined, onCompletion = source.consumes()) {
        source.receive()
    }

    produced.cancel()

    assertFails<Exception> { runTest { source.receive() } }
}

I would expect the test to pass.

[qwwdfsad]

Thanks for your report. I’ve investigated your problem properly, It’s looks like a bug in coroutines+unconfined machinery (or at least it’s a poor-defined interaction between unconfined and other parts of coroutines). Will fix it in the next release

[qwwdfsad]

Thank you again for the report, your issue revealed even bigger problem which may cause unexpected non-determinism (and probably heisenbugs with “Exception in completion handler”) in programs without Unconfined.

I described it under #415 and will fix it there