これはエラーです:
Error processing remote manifest (duplicity-inc.20180712T125810Z.to.20180719T130228Z.manifest.gpg): GPG Failed, see log below:
===== Begin GnuPG log =====
gpg: WARNING: "--no-use-agent" is an obsolete option - it has no effect
gpg: AES256 encrypted data
gpg: encrypted with 1 passphrase
gpg: decryption failed: Bad session key
===== End GnuPG log =====
ここで説明したように、おそらくgpg 2.1へのアップグレードの問題
https://answers.launchpad.net/duplicity/+question/289102
そしてここ
https://answers.launchpad.net/duplicity/+question/288602
ここに記載された回避策
https://superuser.com/questions/984977/duplicity-restore-failing-no-secret-key
..ede/duply.net