I've just gone through all the advice and done the following:
1. removed the unnecessary stuff from my sources.list, including the MATE repository and the mirror I put in for Shrew VPN. (I'll get back to that)
2. ran apt-get with clean, update and upgrade.
The result included the following message:
Code:
The following packages have been kept back:
atril atril-common caja caja-common engrampa engrampa-common eom eom-common google-chrome-stable libmatekbd4 libmateweather-common
linux-image-amd64 mate-applets mate-applets-common mate-control-center mate-core mate-desktop mate-desktop-common
mate-desktop-environment mate-media-common mate-media-gstreamer mate-menus mate-panel mate-panel-common mate-polkit mate-power-manager
mate-power-manager-common mate-screensaver mate-screensaver-common mate-settings-daemon mate-settings-daemon-common
mate-settings-daemon-gstreamer mate-system-monitor mate-utils mate-utils-common
The following packages will be upgraded:
gir1.2-mate-panel libmarco-private0 marco marco-common mate-backgrounds mate-icon-theme mate-media mate-session-manager mate-terminal
mate-terminal-common mate-themes pluma pluma-common
13 upgraded, 0 newly installed, 0 to remove and 35 not upgraded.
So my first question is: What does it mean for a package to be kept back? I skipped ahead in the Admin Handbook to the chapter on packages, but didn't find anything when skimming through.
In other discussions the recommendation was to use an FTP mirror whenever possible. I'd always assumed that the reason was that these are dedicated download sites. k3lt01 has listed a number of straight http URLs in an earlier suggestion on how I should improve my sources.list. I assume when it comes to content, a mirror is a mirror is a mirror, or am I being naive?
One other question about repository URLs which is largely dependnt on the answer to the last one: I currently live in Germany. Wouldn't it be better to use a repository in my "neighbourhood"?? Like "http://ftp.de.debian.org/debian" instead of "http://ftp.debian.org/debian".
The command
apt-get dist upgrade according to the manual is used for new distributions. It is common for people using the
Unstable release to use this on a daily basis. I'm uncertain if it's really necessary at this stage, since it could (theoretically) remove some package I need. I'll dabble with that when I've studied the manual a bit more.
I think I'll mark this as solved, since the original problem was corrected early on. I will, however, keep track of this thread for a while and take note of any new information. If I find out anything particularly relevant myself, I will post it.
Thanks to all who have contributed to my further education in matters concerning Linux.