OK,
thanks - this seems to work. I have modified my /etc/apt/sources.list -file to keep only the PureOS stuff:
deb http://repo.puri.sm/pureos/ green main
deb-src http://repo.puri.sm/pureos/ green main
Then I tried your suggestion, and at first it didn’t work:
# sudo apt clean
# sudo apt update
Get:1 http://repo.puri.sm/pureos green InRelease [10.5 kB]
Get:2 http://repo.puri.sm/pureos green/main Sources [5,341 kB]
Hit:3 https://repo.skype.com/deb stable InRelease
Get:4 http://repo.puri.sm/pureos green/main amd64 Packages [6,243 kB]
Get:5 http://repo.puri.sm/pureos green/main Translation-en [5,557 kB]
Get:6 http://repo.puri.sm/pureos green/main amd64 DEP-11 Metadata [1,955 kB]
Get:7 http://repo.puri.sm/pureos green/main DEP-11 64x64 Icons [7,033 kB]
Fetched 26.1 MB in 8s (3,201 kB/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done
157 packages can be upgraded. Run 'apt list --upgradable' to see them.
# sudo apt full-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
libspice-client-glib-2.0-8 : Depends: gstreamer1.0-plugins-bad but it is not installed
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).
So I needed to do ‘apt --fix-broken install’, which removed the troublesome packages, and then
# sudo apt clean && sudo apt update && sudo apt full-upgrade
ran through without errors (re-installing probably a lot of packages).
I get some warnings at the end:
Processing triggers for initramfs-tools (0.130) ...
update-initramfs: Generating /boot/initrd.img-4.12.0-trunk-amd64
W: Possible missing firmware /lib/firmware/i915/bxt_dmc_ver1_07.bin for module i915
W: Possible missing firmware /lib/firmware/i915/skl_dmc_ver1_26.bin for module i915
W: Possible missing firmware /lib/firmware/i915/kbl_dmc_ver1_01.bin for module i915
W: Possible missing firmware /lib/firmware/i915/kbl_guc_ver9_14.bin for module i915
W: Possible missing firmware /lib/firmware/i915/bxt_guc_ver8_7.bin for module i915
W: Possible missing firmware /lib/firmware/i915/skl_guc_ver6_1.bin for module i915
W: Possible missing firmware /lib/firmware/i915/kbl_huc_ver02_00_1810.bin for module i915
W: Possible missing firmware /lib/firmware/i915/bxt_huc_ver01_07_1398.bin for module i915
W: Possible missing firmware /lib/firmware/i915/skl_huc_ver01_07_1398.bin for module i915
But those were there also before. Don’t think they are problematic.
But now, to install gnome-control-center (which I think I need to get my system settings-icon back) it asks for libcheese8, which asks for gstreamer1.0-plugins-bad (>= 1.4), which asks for
libgstreamer-plugins-bad1.0-0 (= 1.12.2-1) but 1:1.10.4-dmo2 is to be installed
Why would it want to install an old version?
Anyway, I did give the requested version explicitely:
sudo apt-get install libgstreamer-plugins-bad1.0-0=1.12.2-1
and that allowed me to install gnome-control-center, and voila - my system settings are back!
Thanks Mladen!