Comment 12 for bug 1347721

It seems like the issue is the following:

There is a dependency loop mountall->udev->procps->initscripts->mountall. When apt tries to deal with it, it configures them all initially together, then it finds the "libplymouth4" dependency of mountall that is not unpacked yet and inserts the unpack at this point wich breaks the condition that all packages in the loop need to be unpacked at the same time.

        Unpacking mountall:i386 to avoid loop initscripts:i386 Depends on mountall [ i386 ] < 2.53 -> 2.54build1 > ( admin ) (>= 2.28)
          SmartUnPack mountall:i386 (replace version 2.53 with 2.54build1) immediately
          PreDepends order for mountall:i386
          Found ok package dpkg:i386
            SmartConfigure mountall:i386 (2.54build1)
            Unpacking udev:i386 to avoid loop mountall:i386 Depends on udev [ i386 ] < 204-10ubuntu1 -> 208-6ubuntu2 > ( admin )
              SmartUnPack udev:i386 (replace version 204-10ubuntu1 with 208-6ubuntu2) immediately
              PreDepends order for udev:i386
              Found ok package debconf:i386
                SmartConfigure udev:i386 (208-6ubuntu2)
                Unpacking procps:i386 to avoid loop udev:i386 Depends on procps [ i386 ] < 1:3.3.9-1ubuntu2 -> 1:3.3.9-1ubuntu5 > ( admin )
                  SmartUnPack procps:i386 (replace version 1:3.3.9-1ubuntu2 with 1:3.3.9-1ubuntu5) immediately
                    SmartConfigure procps:i386 (1:3.3.9-1ubuntu5)
                    Unpacking libprocps3:i386 to avoid loop procps:i386 Depends on libprocps3 [ i386 ] < 1:3.3.9-1ubuntu2 -> 1:3.3.9-1ubuntu5 > ( libs )
                      SmartUnPack libprocps3:i386 (replace version 1:3.3.9-1ubuntu2 with 1:3.3.9-1ubuntu5) immediately
                      PreDepends order for libprocps3:i386
                      Found ok package multiarch-support:i386
                        SmartConfigure libprocps3:i386 (1:3.3.9-1ubuntu5)
                    Configure already unpacked initscripts [ i386 ] < 2.88dsf-41ubuntu6 -> 2.88dsf-41ubuntu16 > ( admin )
                      SmartConfigure initscripts:i386 (2.88dsf-41ubuntu16) (Only Correct Dependencies)
                    Configure already unpacked initscripts [ i386 ] < 2.88dsf-41ubuntu6 -> 2.88dsf-41ubuntu16 > ( admin )
                      SmartConfigure initscripts:i386 (2.88dsf-41ubuntu16) (Only Correct Dependencies)
            Unpacking libplymouth4:i386 to avoid loop mountall:i386 Depends on libplymouth4 [ i386 ] < none -> 0.9.0-0ubuntu2 > ( libs ) (>= 0.8.1-3)
              SmartUnPack libplymouth4:i386 (install version 0.9.0-0ubuntu2) immediately
              PreDepends order for libplymouth4:i386
              Found ok package multiarch-support:i386
                SmartConfigure libplymouth4:i386 (0.9.0-0ubuntu2)