It’s a bear. For some ungodly reason I was having a really hard time building perl’s Data::Alias on Mountain Lion just now, where trying to build Data::Alias kept blowing up with errors about RETURN_PROBE. The problem proved to be frustratingly ungoogleable, but eventually I found the solution. Add the line
to Alias.xs at some point before
#if defined(USE_DTRACE) && defined(PERL_CORE)
in Alias.xs, make clean, re-run perl Makefile.PL, make, make install.