Well, I went bravely forward with ...
...a bit afraid of GRUB-PC questions (in fact, I think a question YES/NO is shown incorrectly, but not dangerous)...
and finally SUCCESS, the system is updated 100% (well, I think so)
Code: Select all
# apt-get -s dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
In my multiboot system, MBR (sda) is owned by the GRUB of Fedora 20, a distribution that
in my case have never failed. sda8 is for SolydX / Debian. In fact, I have pseudo chains
of GRUB, so I can enter fedora grub tree, choose solydx grub tree, then boot whatever
O.S. I want. No issues
Thank you ALL for yor help.
Maybe later I will comment post-mortem what happened with this, i.e. WHY so hard to
upgrade in MY case. Maybe the key was to remove some solydx-adjustment package or
so, I am not sure; or maybe only the "diversion". Unclear.
I will put this as SOLVED.