Thanks to Kevin Buzzard for spotting that relic of an outmoded version
control system.
If you've obtained the source code by downloading a .tar.gz archive
from the Puzzles web site, you should find several Makefiles in the
source code. However, if you've checked the source code out from the
-Puzzles Subversion repository, you won't find the Makefiles: they're
+Puzzles git repository, you won't find the Makefiles: they're
automatically generated by `mkfiles.pl', so run that to create them.
The Makefiles include: