apt-cache show new version to install but apt-get does nothing

Question

I'm trying to update the plexmediaserver-installer package but when running apt-get upgrade the package is not 'updatable'`

There's my apt-cache command:

apt-cache policy plexmediaserver-installer

plexmediaserver-installer:
  Installed: 1.9.7.4460-a39b25852-1
  Candidate: 1.9.7.4460-a39b25852-1
  Version table:
     1.10.0.4523-648bc61d4-1 -1
         -1 https://dev2day.de/pms jessie/main armhf Packages
 *** 1.9.7.4460-a39b25852-1 100
        100 /var/lib/dpkg/status

It show a new version available (1.10.0.4523-648bc61d4-1) but I can't figure out how to install it

Does someone have an idea?

Thanks

Answer 1

The "newer" package is not installing (unless you force it) because it has been marked with a low priority indicating "do not install".

Notice how in the version table there is a priority to the left of each source under each version. For the first, it's -1, and for the second it's 100.

  Version table:
     1.10.0.4523-648bc61d4-1 -1
         -1 https://dev2day.de/pms jessie/main armhf Packages
 *** 1.9.7.4460-a39b25852-1 100
        100 /var/lib/dpkg/status

Somehow in your APT preferences, you have it configured not to install that other package. Looking at its URL, I'm guessing it's to do with the repository it's coming from: that repository is probably marked as do not install in your config, or there may be an issue with that repository making APT do that itself.

APT priorities

You can modify APT priorities and how they work, but in general they work like this. When a package install or upgrade is requested, a priority is calculated for all available versions of each package and the package with the highest priority is the one installed.

You can use APT pinning (see apt_preferences) to specify any value for a repository, target, or individual package version, but the general values are:

• Less than 0: special value indicating package should never be installed (if you've chosen to block install of a package it'll be -1)
• 100: Currently installed version of a package
• 500: Available package from a different target
• 990: Available package from current default target
• More than 1000: special value indicating package should be installed even if version is lower than current ("force downgrade")

This means that if you already have a package installed, then another package would have to have a priority of over 100 to beat it (and be a newer version, unless it's over 1000).

Answer 2

When forcing the version of plexmediaserver-installer in apt-get command, it seems to work

apt-get install plexmediaserver-installer=1.10.0.4523-648bc61d4-1

But I find this solution a little bit 'forcy'

Answer 3

if you are sure that it should auto update .. you can attempt to set it to auto .. most likely its set in apt to manual update

Do a

sudo apt-mark showmanual | grep plexmediaserver-installer

if it shows an output of the server its set to manual so it wont auto upgrade .. you will need to do

sudo apt-mark auto plexmediaserver-installer=1.10.0.4523-648bc61d4-1

or whatever showed up in the first command then it will be marked as auto .. you can verify by doing

sudo apt-mark showauto | grep plexmediaserver-installer

Be careful tho ... when you do the upgrade ... and it may say some files are not needed use apt-get autoremove to remove them make sure its not removing anything important ... again dont know how this will effect how apt looks at for files that may not be needed and are set for autoremoval...

I knew about this process because my kernel stopped updating and it was a fix for that ... they were set to manual ... but .. on a VM just for giggles .. I set everything to auto to see what would happen .. and autoremove hosed the system ... some things cant be set to auto or the autoremove function can remove files that are needed for the system to run properly :D