In perl 5.26, and some earlier perls that have been proactively
patched (Debian's perl 5.24, for example), '.' was removed from @INC
for security reasons. For details, see:
This breaks the generation scripts which source make.pl with
Although this might be indicative that it's time to refactor these
scripts, I opted for the simplest possible fix for now: restoring '.'
to @INC in each script that depends on make.pl.