git-error

Lenovo-G560:/home/eka# apt-get install git-core
Reading package lists... Done
Building dependency tree
Reading state information... Done
git-core is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue [Y/n]? y
Setting up ruby-rvm (1.6.9-0ubuntu2) ...
dpkg-statoverride: error: syntax error: unknown group 'admin' in statoverride file
dpkg: error processing ruby-rvm (--configure):
 subprocess installed post-installation script returned error exit status 2
Errors were encountered while processing:
 ruby-rvm
E: Sub-process /usr/bin/dpkg returned an error code (1)