> perl -e"use strict; our $x = $x;"
> perl -e"use strict; our $x = qr/(??{ $x })/;"
Variable "$x" is not imported at (re_eval 1) line 2.
Global symbol "$x" requires explicit package name at (re_eval 1) line 2.
Compilation failed in regexp at -e line 1.
> perl -e"use strict; my $x = qr/(??{ $x })/;"
Global symbol "$x" requires explicit package name at (re_eval 1) line 2.
Compilation failed in regexp at -e line 1.