Determine the repo/PPA that a system package came from

[JonoYang]

For system installed packages for Debian or Ubuntu, it would be helpful to know which repo or PPA it came from.

[pombredanne]

May be in /var/lib/apt/lists/ but this is problematic too as it can be commonly removed: https://github.com/search?l=Dockerfile&q="rm++%2Fvar%2Flib%2Fapt%2Flists%2F*"&type=Code

[pombredanne]

See also:

$ apt-cache policy zlib1g
zlib1g:
  Installed: 1:1.2.8.dfsg-2ubuntu4.3
  Candidate: 1:1.2.8.dfsg-2ubuntu4.3
  Version table:
 *** 1:1.2.8.dfsg-2ubuntu4.3 500
        500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages
        100 /var/lib/dpkg/status
     1:1.2.8.dfsg-2ubuntu4 500
        500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages