Thanks for sending detailed information, it helps a lot. Here is the
problem. You don’t have a session manager installed, so the X11 startup
scripts choose to run x-window-manager.
ii metacity [x-window-man 1:2.22.0-2 A lightweight GTK2 based Window Ma
ii twm [x-window-manager] 1:1.0.4-2 Tab window manager
And here, x-window-manager certainly points to metacity. Which is just a
window manager, not something able to start programs.
There is a reason why gdm depends on a session manager (x-window-manager
being a fallback), and a reason why metacity recommends gnome-session.
Many thanks!
I am deeply impressed by the speed of your response but I remained a
little confused because the desk-top manager was working fine before. I
realized since I submitted the report that I had no evidence that the
problem started today because for some weeks, during which I did several
apt-get upgrades, I have not used the desktop. So apologies for filing a
misleading report even though my details led you to diagnose it correctly.
I have installed gnome-session and again obtained a desktop. I now see
that what must have happened is when I was installing/deinstalling python
libraries for a developer-user a few days ago either apt-get install or
autoremove removed gnome-session, at least that is what I deduce from the
careful records I have kept with dpkg --get-selections. This is somewhat
dangerous behaviour from my point of view and I shall be alert in future.
Thanks again.