Just tested, using the same code I used earlier, substituting in each new eval block one at a time without using exit(), i.e.:

#!/usr/bin/perl

use warnings;
use warnings::unused;
use strict;

my $foo = 42;
my $bar = 43;
eval '$'.'foo++';
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Turns out it was easy to install on my Windows machine. It stops behaving "properly" when the eval is in a function. Warnings for both $foo and $bar are emitted as soon as the function is compiled.

#!/usr/bin/perl

use warnings;
use warnings::unused;
use strict;

BEGIN { print("1\n"); }
sub foo {
   my $foo = 42;
   my $bar = 43;
   eval '$foo++';
   print("4\n");
   <>;                     # <-- Segfaults when this is executed.
}                          # <-- Warns when this is compiled
BEGIN { print("2\n"); }
print("3\n");
foo();
print("5\n");
<>;
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... very interesting. On my Debian box, I get a different result, with no segfault.

1
Unused variable my $foo at ./warntest.pl line 9.
Unused variable my $bar at ./warntest.pl line 10.
2
3
4

5
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The blank link after 4 and 5 indicate spots where I pressed return to get it to continue. Did it pass all of the tests in 'make test' in your build environment? My current Windows test box is running ActiveState, so I can't get it to build to test it myself there. One of these days after my current project is finished I plan to rip it out and try Strawberry again.

Interesting! It must produces when the program exits. The existing warning for package variables occurs at compile-time.