{"id":1374,"date":"2016-02-25T18:33:09","date_gmt":"2016-02-25T23:33:09","guid":{"rendered":"http:\/\/osric.com\/chris\/accidental-developer\/?p=1374"},"modified":"2016-02-25T18:33:09","modified_gmt":"2016-02-25T23:33:09","slug":"downgrading-a-debian-package","status":"publish","type":"post","link":"https:\/\/osric.com\/chris\/accidental-developer\/2016\/02\/downgrading-a-debian-package\/","title":{"rendered":"Downgrading a Debian package"},"content":{"rendered":"

After I updated a Debian Wheezy server to Debian Jessie, I was having some problems with VLC. I was using the cvlc to capture and record video streams, but the capture would fail after 2 seconds. A colleague suggested that I leave the OS version alone, but downgrade VLC to confirm that the new version of VLC was causing the problem. A sound idea, but how do you downgrade a Debian package?<\/p>\n

I found a variety of helpful sites and came up with the following:<\/p>\n

    \n
  1. Add the source for the downgraded package the apt config<\/li>\n
  2. Specify the target release in the apt config<\/li>\n
  3. Use “pinning” to tell apt to use the older versions for the package and its dependencies<\/li>\n
  4. Use apt-get install<\/code> to install the dependencies and the package<\/li>\n<\/ol>\n

    Details as follows:<\/p>\n

    Add the source for the downgraded package the apt config<\/strong>
    \nIn this case, I needed to add the
    \nI left my \/etc\/apt\/sources.list<\/code> as-is and added the following to \/etc\/apt\/sources.list.d\/vlc.list<\/code>:<\/p>\n

    deb http:\/\/mirror.cc.columbia.edu\/debian\/ wheezy main non-free contrib
    \ndeb-src http:\/\/mirror.cc.columbia.edu\/debian\/ wheezy main non-free contrib<\/p>\n

    deb http:\/\/security.debian.org\/ wheezy\/updates main contrib non-free
    \ndeb-src http:\/\/security.debian.org\/ wheezy\/updates main contrib non-free<\/p>\n

    deb http:\/\/mirror.cc.columbia.edu\/debian\/ wheezy-updates main contrib non-free
    \ndeb-src http:\/\/mirror.cc.columbia.edu\/debian\/ wheezy-updates main contrib non-free<\/code><\/p>\n

    I used Columbia’s mirror because it’s fast and geographically nearer than most of the other mirrors. I’m sure not all of those sources were necessary (there are no security-related packages in VLC) but it didn’t hurt anything to include them.<\/p>\n

    Specify the target release in the apt config<\/strong>
    \nI added the following to \/etc\/apt\/apt.conf.d\/80targetrelease<\/code> to specify that I want Jessie to be the target\/default release:<\/p>\n

    APT::Default-Release \"jessie\";<\/code><\/p>\n

    Use “pinning” to tell apt to use the older versions for package and its dependencies<\/strong>
    \nI created the file \/etc\/apt\/preferences.d\/vlc<\/code> containing the following. I added to the list of packages as apt-get install<\/code> failed due to missing dependencies. The pin-priority 1001 was suggested by several sites to be used only in the case of downgrading a package.<\/p>\n

    Package: vlc
    \nPin: release n=wheezy
    \nPin-Priority: 1001<\/p>\n

    Package: vlc-data
    \nPin: release n=wheezy
    \nPin-Priority: 1001<\/p>\n

    Package: vlc-nox
    \nPin: release n=wheezy
    \nPin-Priority: 1001<\/p>\n

    Package: libvlc5
    \nPin: release n=wheezy
    \nPin-Priority: 1001<\/p>\n

    Package: libvlccore5
    \nPin: release n=wheezy
    \nPin-Priority: 1001<\/p>\n

    Package: vlc-plugin-notify
    \nPin: release n=wheezy
    \nPin-Priority: 1001<\/p>\n

    Package: vlc-plugin-pulse
    \nPin: release n=wheezy
    \nPin-Priority: 1001<\/p>\n

    Package: xdg-utils
    \nPin: release n=wheezy
    \nPin-Priority: 1001<\/code><\/p>\n

    Use apt-get install to install the dependencies and the package<\/strong>
    \nI started by trying to apt-get install vlc<\/code> but it complained about missing dependencies. I added the dependencies to the preferences file as describe in the section above, and then was able to install the following packages from Debian Wheezy:<\/p>\n

    apt-get install libvlccore5
    \napt-get install vlc-data
    \napt-get install libvlc5
    \napt-get install vlc-nox<\/code><\/p>\n

    Alternatively, I believe I could have skipped the preferences file and setting the pin-priorities by specifying the target Debian version when running apt-get install:<\/p>\n

    apt-get install -t wheezy libvlccore5
    \napt-get install -t wheezy vlc-data
    \napt-get install -t wheezy libvlc5
    \napt-get install -t wheezy vlc-nox<\/code><\/p>\n

    However, I’m not sure that the desired package version would be preserved after running apt-get dist-upgrade<\/code>.<\/p>\n

    References<\/strong>
    \nThe following sites were helpful to me while I was figuring out how to do this, and if you are interested in pin-priority and the different values to use in different scenarios, I definitely recommend the first link:<\/p>\n