Although the installation of GNOME Shell presents no problem, it is useless
alone: most of the MATE applications (in particular setting tools) are indeed
inaccessible, but from a command prompt or a terminal emulator. That
includes the file manager and only installing "gnome-shell" does not put
icons on the desktop! 'mate-menu' would not even start from the terminal.
Anyway, I do not think it would change what GNOME Shell proposes in its dash.
The solution I adopted was to install the "gnome" package. It is simple but
presents the drawback of ending up with pairs of applications serving the
same purpose: MATE Terminal and GNOME Terminal, Pidgin and Empathy,
RhythmBox and GNOME Music, etc. APT asking, I choose GDM3 as the default
display manager. Although I do not know if it is the cause, the graphical
session then crashed. I logged into tty1, executed 'sudo systemctl start
gdm3.service' and could log back into the GNOME session. There now were
icons on the desktop. Weirdly enough, the installation of "gnome" and its
dependencies apparently continued despite the crash of the graphical session.
The default theme has problems. I already mentioned the too-large crosses to
close some windows. However, the problems look more general than that. See
attached a screenshot of the Nautilus window: small and large icons listed
together in the left pane; small and large button at the top; the cross is OK
here. I believe that theme problem affects the default MATE desktop too.
For instance, the launchers, at the left of the panel, look too closely
packed.
I do not know whether 'trisquel-compton-switcher' and 'trisquel-wm-chooser'
are still useful. The former script does not execute because of a
supernumerary character, ^M, at the end of the shebang line. The latter
script looks redundant with the last setting "MATE Tweak" proposes to
setup... and that apparently always turn the graphical session unusable!
I question as well the usefulness of having "Vim", XTerm/UXTerm",
"ImageMagick (display)" in the menu or even installed at all, user-friendly
alternatives being installed as well.
Finally I was happy to not see any GRUB password in Trisquel 8! I hope it
will stay that way.