upgrade hits an acpid problem: "Got no socket."

[Joseph Brenner <doomvox@gmail.com>]

I've been going around on some fun issues related to doing a full
upgrade for the first time in a long time on a Lenovo E550 laptop
running Debian testing.

The system now won't boot cleanly, but I can get in via a
recovery mode (after which, I start network-manager manually), so
I've continued experiment with different apt/dpkg invocations to
see if I can get the system un-wedged.

Where I'm up to in this story-- which I'm cutting short-- is I
had just resolved a conflict between two packages like so:

  dpkg -i --force-overwrite
/var/cache/apt/archives/gnuplot-data_5.2.6+dfsg1-1_all.deb

Then tried this:

  apt-get install -f

But that crashes like this:

  Setting up acpid (1:2.0.31-1) ...
  Job for acpid.service failed because of unavailable resources or
another system error.
  See "systemctl  status acpid.service" and "journalctl  -xe" for details.
  invoke-rc.d: initscript acpid, action "restart" failed.


Looking into this further:

  systemctl  status acpid.service

One learns:

    acpid.service - ACPI event daemon
     Loaded: loaded (/lib/systemd/system/acpid.service; disabled;
vendor preset: enabled)
     Active: failed (Result: resources)
      Tasks: 0 (limit: 4915)
     CGroup: /system.slice/acpid.service

  Apr 18 11:33:38 tango systemd[1]: acpid.service: Got no socket.
  Apr 18 11:33:38 tango systemd[1]: acpid.service: Failed to run
'start' task: Invalid argument
  Apr 18 11:33:38 tango systemd[1]: acpid.service: Failed with result
'resources'.
  Apr 18 11:33:38 tango systemd[1]: Failed to start ACPI event daemon.

Okay: "Got no socket"?

netstat -np showed there were 60-something sockets in use, none
obviously related to ACPI

  netstat -np | wc -l
  71

I tried rebooting, to try to reduce the number of sockets in
use... that cut this count to 36, but I was still seeing that
"Got no socket" error:

  dpkg --configure -a

(Interestingly, the netstat output goes up to 53 lines after
after starting network-manager.  No change in the problems
behavior, though.)

Any ideas?  There's a bunch of "force" options, but I know of
nothing that gets you past a "configure" problem like this.