[1 of 3] Processing sig
  [1 of 1] Compiling Sig[sig]         ( sig\Sig.hsig, nothing )
[2 of 3] Processing impl
  Instantiating impl
  [1 of 1] Compiling Impl             ( impl\Impl.hs, RepPolyBackpack3.out\impl\Impl.o )
[3 of 3] Processing main
  Instantiating main
  [1 of 1] Including sig[Sig=impl:Impl]
    Instantiating sig[Sig=impl:Impl]
    [1 of 1] Compiling Sig[sig]         ( sig\Sig.hsig, RepPolyBackpack3.out\sig\sig-Absk5cIXTXe6UYhGMYGber\Sig.o )

RepPolyBackpack3.bkp:17:5: error: [GHC-15843]
    • Type constructor ‘Rep’ has conflicting definitions in the module
      and its hsig file.
      Main module: type Rep :: GHC.Types.RuntimeRep
                   type Rep = T :: GHC.Types.RuntimeRep
        Hsig file: type Rep :: GHC.Types.RuntimeRep
                   data Rep
      Illegal implementation of abstract data: Invalid type family ‘T’.
    • While checking that ‘impl:Impl’ implements signature ‘Sig’ in ‘sig[Sig=impl:Impl]’.