$ perl -le 'eval { "use gobbledygook;" }; print "ok"'
ok
$ perl -le 'eval { use gobbledygook; }; print "ok"'
Can't locate gobbledygook.pm in @INC ...
$  perl -le 'eval "use gobbledygook;"; print "msg = ($@)" if $@; print "ok"'
msg = (Can't locate gobbledygook.pm in @INC ...)
ok