package ntp 1:4.2.6.p3+dfsg-1ubuntu3 failed to install/upgrade: ErrorMessage: subprocess installed post-installation script returned error exit status 1

Registering documents with scrollkeeper...
Setting up ntp (1:4.2.6.p3+dfsg-1ubuntu3) ...
useradd: cannot lock /etc/passwd; try again later.
adduser: `/usr/sbin/useradd -d /home/ntp -g ntp -s /bin/false -u 128 ntp' returned error code 1. Exiting.
chown: invalid user: `ntp:ntp'
dpkg: error processing ntp (--configure):
 subprocess installed post-installation script returned error exit status 1
Setting up whoopsie (0.1.32) ...
useradd: cannot lock /etc/passwd; try again later.
adduser: `/usr/sbin/useradd -d /nonexistent -g whoopsie -s /bin/false -u 128 whoopsie' returned error code 1. Exiting.
dpkg: error processing whoopsie (--configure):
 subprocess installed post-installation script returned error exit status 1
Setting up libvirt-bin (0.9.8-2ubuntu17) ...
useradd: cannot lock /etc/passwd; try again later.
adduser: `/usr/sbin/useradd -d /var/lib/libvirt/dnsmasq -g libvirtd -s /bin/false -u 128 libvirt-dnsmasq' returned error code 1. Exiting.
dpkg: error processing libvirt-bin (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 ntp
 whoopsie
 libvirt-bin
Log ended: 2012-04-29 13:44:38

Hi Stephen

Thanks for taking the time to report this bug in Ubuntu.

Looks like something has left some .lock files in place on the files used for user management. This does happen from time-to-time.

Have a look in /etc/ for any files ending in *.lock and remove them if they are present - the following should be safe to remove:

   passwd.lock
   shadow.lock
   group.lock

Thanks

Oh - and you should them be able to complete you install using:

   sudo apt-get -f install.