Panic in ghc-9.4-alpha2 building primitive-unlifted

[ 4 of 19] Compiling Data.Primitive.Unlifted.MVar.Primops ( src/Data/Primitive/Unlifted/MVar/Primops.hs, /home/doug/code/haskell-language-server/dist-newstyle/build/x86_64-linux/ghc-9.4.0.20220523/primitive-unlifted-1.0.0.0/build/Data/Primitive/Unlifted/MVar/Primops.o, /home/doug/code/haskell-language-server/dist-newstyle/build/x86_64-linux/ghc-9.4.0.20220523/primitive-unlifted-1.0.0.0/build/Data/Primitive/Unlifted/MVar/Primops.dyn_o )

<no location info>: error:
    panic! (the 'impossible' happened)
  GHC version 9.4.0.20220523:
        findSlot
  Can't find slot
  [PtrUnliftedSlot]
  [PtrLiftedSlot]
  Call stack:
      CallStack (from HasCallStack):
        callStackDoc, called at compiler/GHC/Utils/Panic.hs:182:37 in ghc:GHC.Utils.Panic
        pprPanic, called at compiler/GHC/Types/RepType.hs:266:9 in ghc:GHC.Types.RepType

Please report this as a GHC bug:  https://www.haskell.org/ghc/reportabug

https://github.com/haskell-primitive/primitive-unlifted

commit: 9b16b79318cbe294d3fdf730b8bd0e4191bf422e