[1 of 3] Processing f
  Instantiating f
  [1 of 1] Compiling F                ( f/F.hs, bkp36.out/f/F.o )
[2 of 3] Processing p
  [1 of 2] Compiling A[sig]           ( p/A.hsig, nothing )
  [2 of 2] Compiling P                ( p/P.hs, nothing )
[3 of 3] Processing q
  [1 of 2] Compiling B[sig]           ( q/B.hsig, nothing )
  [2 of 2] Compiling Q                ( q/Q.hs, nothing )

bkp36.bkp:20:16: warning: [-Wdeprecations (in -Wdefault)]
    In the use of type constructor or class ‘T’ (imported from B):
    "Inherited requirements from non-signature libraries (libraries with modules) should not be used, as this mode of use is not compatible with PVP-style version bounds.  Instead, copy the declaration to the local hsig file or move the signature to a library of its own and add that library as a dependency."