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

bkpfail33.bkp:5:18: error:
    • Not in scope: type constructor or class ‘T’
    • while merging the signatures from:
        • p[A=<A>]:A
        • ...and the local signature for A