I'm getting ``` <no location info>: error: panic! (the 'impossible' happened) GHC version 9.6.2: collectNBinders 1 Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/GHC/Utils/Panic.hs:189:37 in ghc:GHC.Utils.Panic pprPanic, called at compiler/GHC/Core.hs:2050:25 in ghc:GHC.Core CallStack (from HasCallStack): panic, called at compiler/GHC/Utils/Error.hs:454:29 in ghc:GHC.Utils.Error ``` Repro: with GHC 9.6.2 run: cabal test simplifiedOnlyTest -ftest_seq --enable-optimization --allow-newer=base on commit https://github.com/Mikolaj/horde-ad/commit/a9ea6e930f3561d90237cf8a431b8aad24387c8e 9.8.1-alpha with head.hackage compiles fine (but `--allow-newer=base` doesn't suffice, so I can't try the exact same commandline as with GHc 9.6.2). GHC 9.4.6 with and without `--allow-newer=base` compiles fine. Similar issues: https://gitlab.haskell.org/ghc/ghc/-/issues/13413 https://gitlab.haskell.org/ghc/ghc/-/issues/15002 https://gitlab.haskell.org/ghc/ghc/-/issues/15108