Thank you so much for figuring this out. I've filed a bug at
https://gitlab.haskell.org/ghc/ghc/-/issues/22549
In the mean time, I'll adjust the upper bounds on Hackage and release a version
of logict-sequence that hopefully won't have this issue.
On Thu, Dec 1, 2022 at 7:14 PM Li-yao Xia
GHC 9.4.3 with -O2 is miscompiling the derived Show and Eq instances for SeqT in logict-sequence.
main :: IO () main = print (pure 0 :: Seq Int) -- -O0, -O1: prints the Seq -- -O2: <<loop>>
On top of that, both hedgehog and hspec fail to catch `<<loop>>`.
main :: IO () main = defaultMain [ check $ property $ do let x = x :: Int -- obvious loop compiles to a thrown exception <<loop>> if x == x then pure () else pure () ] -- "thread blocked indefinitely in an STM transaction" -- meaning some thread is not getting cleaned up properly
main :: IO () main = hspec $ do describe "work" $ do it "works" $ do let x = x :: Int -- obvious loop compiles to a thrown exception <<loop>> if x == x then pure () else pure () :: IO () --- hangs
Cheers, Li-yao
On 2022-11-30 10:33 PM, David Feuer wrote:
The logict-sequence test suite consistently freezes up on the last test when compiled with GHC 9.4.3. logict-sequence and its test suite don't do anything special with that GHC/base version as far as I can see, or anything particularly strange in general, so I'm pretty confident the problem lies elsewhere. My best guesses are hedgehog, tasty, and tasty-hedgehog. Has anyone else run into weird issues with any/all of these on GHC 9.4.3?
David _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.