On cygwin 1.5.21-2 with perl 5.8.7 I get a parse error on the second variation...(which seems normal given the lonely doublequote at the end of the eval no??) Devel::Size is 0.59 which seems to be old (latest is 0.63)

UPDATE: with the modification indicated by shmem, I get the same result in both cases. latest version of Devel::Size is 0.64 (not 0.63) so the problem could also come from there

% stephan@armen (/home/stephan) %
% perl -MDevel::Size -e 'print $Devel::Size::VERSION'
0.59


% stephan@armen (/home/stephan) %
% ./devel_size_test.px   
Devel::Size: Calculated sizes for CVs are incomplete
108
Devel::Size: Calculated sizes for CVs are incomplete
108
sub2 args('main','./devel_size_test.px','19','main::__ANON__','1','','
+','','2','UUUUUUUUUUUU')

Hullo, monkses!

sub1 args('main','./devel_size_test.px','20','main::__ANON__','1','','
+','','2','UUUUUUUUUUUU')

Howdy, world!


% stephan@armen (/home/stephan) %
% ./devel_size_test2.px
Warning: Use of "require" without parentheses is ambiguous at (eval 1)
+ line 1.
String found where operator expected at (eval 1) line 1, at end of lin
+e
Can't find string terminator '"' anywhere before EOF at (eval 1) line 
+1.


% stephan@armen (/home/stephan) %
% diff devel_size_test@(|2).px
2d1
< 
7,10c6,8
<     my $file = shift;
<     my $sub  = \eval "package ".caller()."; require \"$file\"";
<     my $foo  = sub { goto $$sub };
<     $foo;
---
>     my $sub = \eval 'package '.caller().'; require '.shift(@_).'"';
>     die $@ if $@;
>     sub { goto $$sub };
21d18
<
[download]

hth --stephan