How to use gpg command-line to check passphrase is correct

Question

I am trying to automate backups with duplicity, but when I test the result, I get

gpg: public key decryption failed: bad passphrase

Answer 1

For me the simplistic way to check the passphrase is to use gpg --passwd shorthand. It tries to change the passphrase and the step is to confirm the old passphrase, and then you can click 'cancel' on the new passphrase prompt and this keeps the passphrase intact.

gpg --passwd