GHC 9.4.5 hangs when compiling with -O1, but compilation suceeds with -O0 and also with -O1 with GHC 9.6.2 and 9.2.7
Not minimized in any way. You can recognize the freeze on your machine by CPU usage going down to (almost) none and staying there for 0.5h and probably forever. Replicated in CI
https://github.com/Mikolaj/horde-ad/actions/runs/5348240002/jobs/9697857434
Happens at this commit
https://github.com/Mikolaj/horde-ad/commit/bbcfeadce17591b09fce326f23570c5dec8cd3fb
when running
cabal test simplifiedOnlyTest -ftest_seq --enable-optimization
(but also cabal build
, which however takes longer to get there).