GnuPG.pm - Symmetric file encryption

[sean_abel]

When using GnuPG from the command line I can encrypt a file with no
recipient. When I try to do this through Perl I get an error to that
effect.

Any ideas?

command line:

 gpg --output file.gpg --symmetric file.txt

perl code:

$gpg->encrypt( plaintext => 'test/file.txt',
                          output => "test/file.gpg",
                          sign => 1,
                          passphrase => "$passphrase"
                         );

Thanks in advance!

Sean