You can also hand-tweak your config.h to try out different #ifdef
branches.
-=head1 Purify runs
+=head1 Running Purify
Purify is a commercial tool that is helpful in identifying memory
overruns, wild pointers, memory leaks and other such badness. Perl
make all pureperl
cd t
ln -s ../pureperl perl
+ setenv PERL_DESTRUCT_LEVEL 5
./perl TEST
Disabling Perl's malloc allows Purify to monitor allocations and leaks