[1 of 3] Processing p
  [1 of 2] Compiling A[sig]           ( p/A.hsig, nothing )
  [2 of 2] Compiling B[sig]           ( p/B.hsig, nothing )
[2 of 3] Processing i
  Instantiating i
  [1 of 1] Compiling A                ( i/A.hs, bkpfail41.out/i/A.o )
[3 of 3] Processing r
  [1 of 2] Compiling B[sig]           ( r/B.hsig, nothing )
  [2 of 2] Instantiating p

bkpfail41.bkp:10:9: error:
    • Class ‘C’ has conflicting definitions in the module
      and its hsig file
      Main module: type C :: * -> Constraint
                   class C a where
                     f :: a -> a
                     {-# MINIMAL f #-}
      Hsig file:  type C :: * -> Constraint
                  class C a where
                    f :: a -> a
                    default f :: a -> a
      The methods do not match:
        The default methods associated with ‘f’ are not compatible
      The MINIMAL pragmas are not compatible
    • while checking that i:A implements signature A in p[A=i:A,B=<B>]