use strict;
use warnings;

{
   my $f = 'test';
   my $g = 'test';

   sub f {
      sub { print "f: $f\n" }->();
   }

   sub g {
      $g if 0;
      sub { print "g: $g\n" }->();
   }
}

f();
g();

##</code><code>##

>perl589\bin\perl test.pl
Use of uninitialized value in concatenation (.) or string at test.pl line 9.
f:
g: test

>perl5100\bin\perl test.pl
f: test
g: test

##</code><code>##

>perl589\bin\perl -wle"{ my $s='test'; sub f { print 's: ', eval '$s' } } f()"
Use of uninitialized value in print at -e line 1.
s: 

>perl5100\bin\perl -wle"{ my $s='test'; sub f { print 's: ', eval '$s' } } f()"
Variable "$s" is not available at (eval 1) line 2.
Use of uninitialized value in print at -e line 1.
s: