$SIG{__DIE__} = sub { print '>', @_, "<\n"};

##</code><code>##

>No such field 'USERx' at /usr/lib/perl5/site_perl/5.8.5/WWW/Mechanize.pm line 1033
<
No such field 'USERx' at /usr/lib/perl5/site_perl/5.8.5/WWW/Mechanize.pm line 1033
>Trying to call non existing method at /home/myscript.pl line 0
<