GHCi tests hanging on Mac

Ben Gamari ben at
Fri Jul 14 16:14:31 UTC 2017

Richard Eisenberg <rae at> writes:

> Hi devs,
> Some GHCi tests (but far from all!) hang on my Mac. I can't reproduce
> this behavior outside the testsuite driver, so I think it's the Python
> code, not the Haskell.
> Failing tests:
>   ghci/prog017/prog017
>   ghci/scripts/T6018ghcifail
>   ghci/scripts/T6018ghcirnfail
> And that's it! My Python reports that it's 2.7.13.
Hmm, well that is concerning. As far as I can tell the only thing that
these tests share is that their scripts are relatively long. However,
they aren't unique in this regard; if this were the cause I would have
also expected, for instance, T2182ghci and T11524a to fail as well.

Is it really always this set of tests that fail? Do they fail reliably?

Are you certain you are running the test in the same way that the
testsuite driver is (specifically, piping the script to stdin of the
ghci process)? I just looked at the driver implementation and it seems
to me that it could be simplified a bit. Does D3735 help? It's
admittedly a stab in the dark, but Python has surprised me in the past.


- Ben
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 487 bytes
Desc: not available
URL: <>

More information about the ghc-devs mailing list