$ perl -wMstrict -le '     print join ",", File::Glob::bsd_glob("{x,y}={a,b}")'
Undefined subroutine &File::Glob::bsd_glob called at -e line 1.
$ perl -wMstrict -le '<*>; print join ",", File::Glob::bsd_glob("{x,y}={a,b}")'
x=a,x=b,y=a,y=b