Hi, I have same issue.
Fixed by a rollback ---- tchet@quieter:~/git$ dput ftp-master dh-virtualenv_1.2.2-1.5_source.changes Checking signature on .changes gpg: /home/tchet/git/dh-virtualenv_1.2.2-1.5_source.changes: Valid signature from 31F3144544A1741A Checking signature on .dsc gpg: /home/tchet/git/dh-virtualenv_1.2.2-1.5.dsc: Valid signature from 31F3144544A1741A Incorrect delayed argument: ValueError: delayed days value must be a decimal integer: tchet@quieter:~/git$ apt policy dput dput: Installé : 1.2 Candidat : 1.2 Table de version : *** 1.2 502 450 http://ftp.be.debian.org/debian unstable/main amd64 Packages 450 http://ftp.be.debian.org/debian unstable/main i386 Packages 100 /var/lib/dpkg/status 1.1.3 501 501 http://ftp.be.debian.org/debian testing/main amd64 Packages 501 http://ftp.be.debian.org/debian testing/main i386 Packages tchet@quieter:~/git$ sudo apt install dput=1.1.3