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Arun
Asked: 2017-06-04 20:54:52 +0800 CST

How are repository details specified in apt?

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I ran apt list --installed command and got this output:

xterm/xenial,now 322-1ubuntu1 amd64 [installed]
xul-ext-ubufox/xenial,now 3.2-0ubuntu1 all [installed]
xz-utils/xenial,now 5.1.1alpha+20120614-2ubuntu2 amd64 [installed]
yelp/xenial,now 3.18.1-1ubuntu4 amd64 [installed]
yelp-xsl/xenial,now 3.18.1-1 all [installed]
zeitgeist-core/xenial,now 0.9.16-0ubuntu4 amd64 [installed]
zeitgeist-datahub/xenial,now 0.9.16-0ubuntu4 amd64 [installed]
zenity/xenial,now 3.18.1.1-1ubuntu2 amd64 [installed]
zenity-common/xenial,now 3.18.1.1-1ubuntu2 all [installed]
zip/xenial,now 3.0-11 amd64 [installed]
zlib1g/unknown,xenial-updates,now 1:1.2.8.dfsg-2ubuntu4.1 amd64 [installed]

Why unknown instead of xenial when updated from local repository?

What is this now repository?

repository

1 Answers

  1. Best Answer

    unknown

    The unknown part comes from the entry for Suite key in Release file for a debian repository. I think you've generated a local repository without properly setting the required keys for the Release (or InRelease )file and that's why apt shows unknown.

    For example, a typical standard Release file may have these entries (taken from Ubuntu's official repository's InRelease file)

    Origin: Ubuntu
Label: Ubuntu
Suite: zesty
Version: 17.04
Codename: zesty
Date: Wed, 12 Apr 2017  2:53:23 UTC
Architectures: amd64 arm64 armhf i386 ppc64el s390x

    Check this section of debian wiki for more information about Release file format.

    And check this slightly old but my favorite guide to create a proper Ubuntu local repository.

    now

    now refers to the version of the package currently installed (and thus considered available). The info is maintained in /var/lib/dpkg/status file. I have these entries in apt list --installed

    zlib1g/zesty,now 1:1.2.11.dfsg-0ubuntu1 amd64 [installed]
zlib1g-dev/ubuntu-local,zesty,now 1:1.2.11.dfsg-0ubuntu1 amd64 [installed,automatic]
zsync/zesty,now 0.6.2-2ubuntu1 amd64 [installed]

    As you can see zsync has a now entry which means it's installed and available as such. If you see no other entries except now it would mean you have a package installed which isn't available to reinstall from any known repository.

    Here is the output of apt policy zsync again from the same system.

    zsync:
  Installed: 0.6.2-2ubuntu1
  Candidate: 0.6.2-2ubuntu1
  Version table:
 *** 0.6.2-2ubuntu1 500
        500 http://bd.archive.ubuntu.com/ubuntu zesty/universe amd64 Packages
        100 /var/lib/dpkg/status
     0.6.2-1ubuntu1 500
        500 file:/mnt/Data/Software/Linux/Debian_Packages/xenial_debs2  Packages

    As you can see /var/lib/dpkg/status was listed as a repo for zsync which means it's currently installed.

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