[1 of 3] Processing p
  [1 of 1] Compiling A[sig]           ( p/A.hsig, nothing )
[2 of 3] Processing q
  Instantiating q
  [1 of 1] Compiling A                ( q/A.hs, bkpfail37.out/q/A.o )
[3 of 3] Processing r
  Instantiating r
  [1 of 1] Including p[A=q:A]
    Instantiating p[A=q:A]
    [1 of 1] Compiling A[sig]           ( p/A.hsig, bkpfail37.out/p/p-HVmFlcYSefiK5n1aDP1v7x/A.o )

bkpfail37.bkp:9:9: error:
    • Identifier ‘op’ has conflicting fixities in the module
      and its hsig file
      Main module: infixr 4
      Hsig file: infixr 6
    • while checking that q:A implements signature A in p[A=q:A]