Debian: GPG Error - NO_PUBKEY about profile-cleaner

[graysky2]

Ah, ever since psd as accepted into the Debian repos, I haven't been doing much w/ the PPA. I will look into this.

[kepi]

In my case (debian unstable) error was "repository ... quantal Release is not signed."

Changing quantal in sources list to zesty fixed it

[keypey]

I change repo to quantal and add key
W: Błąd GPG: http://ppa.launchpad.net/graysky/utils/ubuntu quantal Release: Następujące podpisy nie mogły zostać zweryfikowane z powodu braku klucza publicznego: NO_PUBKEY C1C5C63BF0E0B4E7 E: The repository 'http://ppa.launchpad.net/graysky/utils/ubuntu quantal Release' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.

Linux thinkc 4.9.0-6-amd64 #1 SMP Debian 4.9.82-1+deb9u3 (2018-03-02) x86_64 GNU/Linux,
Distributor ID: Debian
Description: Debian GNU/Linux 9.4 (stretch)
Release: 9.4
Codename: stretch