[1 of 3] Processing p
  [1 of 1] Compiling A[sig]           ( p/A.hsig, nothing )
[2 of 3] Processing q
  [1 of 1] Compiling A[sig]           ( q/A.hsig, nothing )
[3 of 3] Processing r
  [1 of 4] Compiling A[sig]           ( r/A.hsig, nothing )

bkpfail04.bkp:7:9: error:
    • Type constructor ‘A’ has conflicting definitions in the module
      and its hsig file
      Main module: type A :: *
                   data A = A {foo :: Int}
      Hsig file:  type A :: *
                  data A = A {bar :: Bool}
      The constructors do not match:
        The record label lists for ‘A’ differ
        The types for ‘A’ differ
    • while merging the signatures from:
        • p[A=<A>]:A
        • q[A=<A>]:A
        • ...and the local signature for A