to trigger/signal a rebuild for the transition 5.8.8 -> 5.10.0.
The list of packages is computed by finding all packages which end
up having either of PERL5_USE_PACKLIST, BUILDLINK_API_DEPENDS.perl,
or PERL5_PACKLIST defined in their make setup (tested via
"make show-vars VARNAMES=...").
This Perl module is useful for writers of daemons and other processes
that need to tell whether they are already running, in order to prevent
multiple process instances. The module accomplishes this via *nix-style
pidfiles, which are files that store a process identifier.