update-manager blocked waiting for non-existent other package manager

[Steve Beattie]

Binary package hint: update-manager

update-manager is unable to check for new updates (update the package lists) or install available updates due to blocking on a lock; see the attached screen shot. There does not appear to be any other package manager running, ps reports only update-notifier, aptd, and update-manager itself running; there's no apt, dpkg, synpatic, or software store processes running.

lsof shows only update-manager itself holding the /var/lib/dpkg/lock file:

$ sudo lsof | grep dpkg
lsof: WARNING: can't stat() fuse.gvfs-fuse-daemon file system /home/ubuntu/.gvfs
      Output information may be incomplete.
update-ma 2067 root 16uW REG 8,1 0 118154 /var/lib/dpkg/lock
update-ma 2067 root 17uW REG 8,1 0 118154 /var/lib/dpkg/lock
update-ma 2067 root 32r REG 8,1 1290808 540 /var/lib/dpkg/status

ProblemType: Bug
Architecture: amd64
Date: Fri Sep 25 09:42:51 2009
DistroRelease: Ubuntu 9.10
Package: update-manager 1:0.125.4
PackageArchitecture: all
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-10.35-generic
SourcePackage: update-manager
Uname: Linux 2.6.31-10-generic x86_64

[Michael Vogt (mvo)]

This is fixed since.