Bus error when gv_init is given a undef scalar > SVt_NULL

If I insert this at the beginning of gv.c/Perl_gv_init, before the declaration of old_type:

  SvUPGRADE(gv,SVt_IV);

then I get a bus error when I run perl.

I have not yet determined what the exact cause is, nor have I found a way to trigger this from Perl. A patch I am working on ended up triggering this.

Any ideas?

• Bus error when gv_init is given a undef scalar > SVt_NULL by Father Chrysostomos