(innermost) subroutine is referencing a lexical variable defined in
the outermost subroutine. For example:
- sub outermost { my $x; sub middle { sub { $x } } }
+ sub outermost { my $a; sub middle { sub { $a } } }
If the anonymous subroutine is called or referenced (directly or
indirectly) from the outermost subroutine, it will share the variable