$ sudo dpkg -i libgl1-mesa_6.5.1-0ubuntu8_amd64.deb
dpkg: considering removing libgl1-mesa-dri in favour of libgl1-mesa ...
dpkg: no, cannot remove libgl1-mesa-dri (--auto-deconfigure will help):
x-window-system-core depends on libgl1-mesa-dri
libgl1-mesa-dri is to be removed.
dpkg: regarding libgl1-mesa_6.5.1-0ubuntu8_amd64.deb containing libgl1-mesa:
libgl1-mesa conflicts with libgl1-mesa-dri (<< 6.5.0)
libgl1-mesa-dri (version 6.4.1-0ubuntu8) is installed.
dpkg: error processing libgl1-mesa_6.5.1-0ubuntu8_amd64.deb (--install):
conflicting packages - not installing libgl1-mesa
Errors were encountered while processing:
libgl1-mesa_6.5.1-0ubuntu8_amd64.deb