[1 of 4] Processing p
  [1 of 2] Compiling A[sig]           ( p\A.hsig, nothing )
  [2 of 2] Compiling B                ( p\B.hs, nothing )
[2 of 4] Processing q
  [1 of 2] Compiling A[sig]           ( q\A.hsig, nothing )
  [2 of 2] Instantiating p
[3 of 4] Processing aimpl
  Instantiating aimpl
  [1 of 1] Compiling A                ( aimpl\A.hs, bkpfail35.out\aimpl\A.o )
[4 of 4] Processing r
  Instantiating r
  [1 of 1] Including q[A=aimpl:A]
    Instantiating q[A=aimpl:A]
    [1 of 1] Compiling A[sig]           ( q\A.hsig, bkpfail35.out\q\q-E72T6bb4XRkIeTPWK2mCKa\A.o )

bkpfail35.out\q\q-E72T6bb4XRkIeTPWK2mCKa\..\A.hi:1:1: error: [GHC-93011]
    • ‘y’ is exported by the hsig file, but not exported by the implementing module ‘aimpl:A’
    • While checking that ‘aimpl:A’ implements signature ‘A’ in ‘q[A=aimpl:A]’.