T8089 mysteriously fails when GHC is built with LLVM (#15064) · Issues · Glasgow Haskell Compiler / GHC

T8089 mysteriously fails when GHC is built with LLVM

CircleCI's LLVM build revealed that T8089 fails. The test is quite simple,

main = threadDelay maxBound

and is expected to timeout. However, it somehow exits with code 0 in all ways when built with LLVM.

This didn't reproduce when I tried make test TEST=T8089 EXTRA_HC_OPTS=-fllvm locally, so either it's a library issue or environment-sensitive.

Trac metadata

Trac field	Value
Version	8.2.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler (LLVM)
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture

CircleCI's LLVM build revealed that `T8089` fails. The test is quite simple,

```hs
main = threadDelay maxBound
```

and is expected to timeout. However, it somehow exits with code 0 in all ways when built with LLVM.

This didn't reproduce when I tried `make test TEST=T8089 EXTRA_HC_OPTS=-fllvm` locally, so either it's a library issue or environment-sensitive.

<details><summary>Trac metadata</summary>

| Trac field             | Value           |
| ---------------------- | --------------- |
| Version                | 8.2.2           |
| Type                   | Bug             |
| TypeOfFailure          | OtherFailure    |
| Priority               | normal          |
| Resolution             | Unresolved      |
| Component              | Compiler (LLVM) |
| Test case              |                 |
| Differential revisions |                 |
| BlockedBy              |                 |
| Related                |                 |
| Blocking               |                 |
| CC                     |                 |
| Operating system       |                 |
| Architecture           |                 |

</details>