try

#!/usr/bin/perlml
use CGI::Carp qw(fatalsToBrowser);
print "content-type: text/plain\n\nTesting";
#use LWP::UserAgent;
use Data::Dumper;
print '<pre>';
print Dumper(\%ENV);
print Dumper(\@INC);
print Dumper(\%INC);
print '</pre>';
[download]

Notice i commented out the lwp use.

if that works then try

#!/usr/bin/perlml
use CGI::Carp qw(fatalsToBrowser);
use Data::Dumper;
print "content-type: text/plain\n\nTesting";
print '<pre>';

eval {require LWP::UserAgent; } ; 
print 'possible require ERROR:'.$@."\n" if ($@); 

eval {require x::x; } ;
print 'possible require ERROR:'.$@."\n" if ($@); 

print Dumper(\%ENV);
print Dumper(\@INC);
print Dumper(\%INC);
print '</pre>';
[download]

notice the change to a require in an eval. and x::x to prove it does fail right.

edit: dayum forgot "use Data::Dumper;"