Previously the output was:

    Building profunctors-5.2 lib...
    Building semigroupoids-5.1...

Now it is:

    Building profunctors-5.2 (lib)...
    Building semigroupoids-5.1 (all, due to Custom setup)...

Fixes #3808.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>