Comment 183 for bug 553745

At long last, I can now recreate this problem at will.

Although I haven't debugged the actual cause yet (and hence don't yet have a fix), it is triggered when the following occur "very close together":

    plymouth show-splash
    plymouth quit

Note that the problem can occur on boot (where plymouthd is run with '--mode=boot') and shutdown (where plymouthd is run with '--mode=shutdown').

For those interested, to recreate the problem:

# in 1 window...
$ sudo apt-get install plymouth-x11
$ ./test_plymouth.sh -s /sbin/plymouthd

# in another window
$ ./force_crash.sh

After a few seconds, a crash will occur.

test_plymouth.sh and force_crash.sh are available here:

  http://people.canonical.com/~jhunt/plymouth/

What I can see currently is that objects are being corrupted and a repeating pattern appears to be timeout/pending calls.

Further investigation is required, but atleast once we have a fix available, we now have a way to test it.