Thanks! Gotta learn to actually read the error messages... The failing line is an "eval { require Carp::Heavy }". This goes away when not including the core with -B.

Unfortunately, now I get "Can't locate PAR/Heavy.pm". Even explicitly including the module using -M, as in

pp -P -M PAR::Heavy -o scandeps.par.pl `which scandeps.pl`

doesn't work, still the same error. I verified that the module gets included, but it isn't found at runtime.