$ perl -le " sub foo { die @_ }; package OTHER; foo( 666 ) "
Undefined subroutine &OTHER::foo called at -e line 1.

$ perl -le " sub foo { die @_ }; package OTHER; main::foo( 666 ) "
666 at -e line 1.

$ perl -le " sub foo { die @_ }; package OTHER; ::foo( 666 ) "
666 at -e line 1.