Panic with repSplitAppTys

I get a GHC panic while compiling a rather large module that contains a fairly simple function:

import Control.Monad.Reader
usingReader ::
  (Monad m) =>
  r ->
  (a -> ReaderT r m b)
  (a -> m b)
usingReader r f = flip runReaderT r . f

Unfortunately, that function alone in a module does not trigger the panic. The error message is:

ghc: panic! (the 'impossible' happened)
  (GHC version 8.2.1 for x86_64-unknown-linux):
	repSplitAppTys
  a_ahFs[sk:1]
  ReaderT r_ahFr[sk:1] m_ahFq[sk:1] b_ahFt[sk:1]
  []
  Call stack:
      CallStack (from HasCallStack):
        prettyCurrentCallStack, called at compiler/utils Outputable.hs:1133:58 in ghc:Outputable
        callStackDoc, called at compiler/utils/Outputable.hs:1137:37 in ghc:Outputable
        pprPanic, called at compiler/types/Type.hs:808:9 in ghc:Type

Trac metadata

Trac field	Value
Version	8.2.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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