With my version of gdb, that would be gdb -p 1234.

When doing this, it is often useful to ask Perl to tell you where it is. For that, I do p Perl_warner(my_perl, 1, "oops"), which will print out something like "oops at Snorkus.pm line 56".

That may require debug symbols. You can install the perl-debuginfo RPM if you can find it. (I got it via rpmbuild --rebuild perl-*.src.rpm)

Or you could do something like p Perl_eval_pv(my_perl, "use Carp; Carp::cluck('oops')", 0) to get a full stack trace.