I had a great cloud running, but some configuration changed and I removed nova-compute. I then attempted to reinstall it, but I'm getting an error I can't solve. Any help is greatly appreciated.

I'm running Ubuntu 12.04 and OpenStack Grizzly. My OpenStack source list is:

deb http://ubuntu-cloud.archive.canonical.com/ubuntu precise-updates/grizzly main

This is the error:

sudo apt-get install nova-compute
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
  nova-common nova-compute-kvm python-nova python-novaclient
The following NEW packages will be installed:
  nova-common nova-compute nova-compute-kvm python-nova python-novaclient
0 upgraded, 5 newly installed, 0 to remove and 1 not upgraded.
Need to get 2,790 kB/2,816 kB of archives.
After this operation, 25.1 MB of additional disk space will be used.
Do you want to continue [Y/n]? y
Get:1 <a href="http://ubuntu-cloud.archive.canonical.com/ubuntu/">http://ubuntu-cloud.archive.canonical.com/ubuntu/</a> precise-updates/grizzly/main python-novaclient all 1:2.13.0-0ubuntu1~cloud0 [84.6 kB]
Get:2 <a href="http://ubuntu-cloud.archive.canonical.com/ubuntu/">http://ubuntu-cloud.archive.canonical.com/ubuntu/</a> precise-updates/grizzly/main python-nova all 1:2013.1.2-0ubuntu1~cloud0 [2,695 kB]
Get:3 <a href="http://ubuntu-cloud.archive.canonical.com/ubuntu/">http://ubuntu-cloud.archive.canonical.com/ubuntu/</a> precise-updates/grizzly/main nova-compute-kvm all 1:2013.1.2-0ubuntu1~cloud0 [2,802 B]
Get:4 <a href="http://ubuntu-cloud.archive.canonical.com/ubuntu/">http://ubuntu-cloud.archive.canonical.com/ubuntu/</a> precise-updates/grizzly/main nova-compute all 1:2013.1.2-0ubuntu1~cloud0 [7,808 B]
Fetched 2,790 kB in 2s (1,132 kB/s)       
Selecting previously unselected package python-novaclient.
(Reading database ... 214746 files and directories currently installed.)
Unpacking python-novaclient (from .../python-novaclient_1%3a2.13.0-0ubuntu1~cloud0_all.deb) ...
Selecting previously unselected package python-nova.
Unpacking python-nova (from .../python-nova_1%3a2013.1.2-0ubuntu1~cloud0_all.deb) ...
Selecting previously unselected package nova-common.
Unpacking nova-common (from .../nova-common_1%3a2013.1.2-0ubuntu1~cloud0_all.deb) ...
Selecting previously unselected package nova-compute-kvm.
Unpacking nova-compute-kvm (from .../nova-compute-kvm_1%3a2013.1.2-0ubuntu1~cloud0_all.deb) ...
Selecting previously unselected package nova-compute.
Unpacking nova-compute (from .../nova-compute_1%3a2013.1.2-0ubuntu1~cloud0_all.deb) ...
Processing triggers for man-db ...
Processing triggers for ureadahead ...
Setting up python-novaclient (1:2.13.0-0ubuntu1~cloud0) ...
Setting up python-nova (1:2013.1.2-0ubuntu1~cloud0) ...
Setting up nova-common (1:2013.1.2-0ubuntu1~cloud0) ...
usermod: no changes
Command failed, please check log for more info
2013-07-29 16:33:55.589 7511 CRITICAL nova [-] <VerNum(83)>
2013-07-29 16:33:55.589 7511 TRACE nova Traceback (most recent call last):
2013-07-29 16:33:55.589 7511 TRACE nova   File "/usr/bin/nova-manage", line 1263, in <module>
2013-07-29 16:33:55.589 7511 TRACE nova     main()
2013-07-29 16:33:55.589 7511 TRACE nova   File "/usr/bin/nova-manage", line 1255, in main
2013-07-29 16:33:55.589 7511 TRACE nova     fn(*fn_args, **fn_kwargs)
2013-07-29 16:33:55.589 7511 TRACE nova   File "/usr/bin/nova-manage", line 798, in sync
2013-07-29 16:33:55.589 7511 TRACE nova     return migration.db_sync(version)
2013-07-29 ...