How can I reinstall the Unity Launcher

[Gerry Boland]

On Mon 07 Nov 2011 15:12:44 CET, Udvarias Ur wrote:
>
> I'm a first time user of this list, though I have been an
> administrator of a number of lists using the Mailman software.
>
> I have a problem I can not seem to solve, regardless of years of
> experience with AT&T Unix, SCO Unix, Interactive Unix, Unixware, and
> Irix. It seems to have been triggered by the same problem that Jim
> Byrnes and Colin Law encountered in October 2011.
>
> * I read some of the help for Unity, to find a way to configure it.
> * I found mention of the Compiz settings manager. (I don't remember
> the exact name.)
> So I installed it.
> * After changing only it's size and position the Launcher ceased to
> behave properly.
> * Even resetting all the variables to their defaults, from inside the
> Compiz settings manager,
> would not return the Launcher to it's default behaviour.

You could try

sudo apt-get install --reinstall unity

just to see if it helps.

>
> * I removed the launcher, intending to re-install it, to re-establish
> the default behaviour.
> * Unfortunately I rebooted the system before I re-install the Launcher.
> * Logging in at the GUI pops up a small dialogue that reads
> 'Failed to load session "ubuntu"'
> with a
> Logout
> button.
>
> * Now I can only get into the system as root in recovery mode.
>
> * All my data is on second hard disk that can be accessed by both
> Windows and Ubuntu so I can
> re-install Ubuntu.
> * However I spent a lot of time installing software and configuring
> Ubuntu to work the way
> I want it to.
> So, I'd rather not go through that again, though if push came to shove
> I could start all
> over from scratch.
>
> * I thought editing the .loginrc would get me back in so I could
> re-install the Launcher.
> * However, Ubuntu (Linux?) doesn't have one that I could find.
>
> * With my Windows system I downloaded all the Unity 2d packages from
> ca.archive.ubuntu.org.
> * Booting into the root console, mounting the Windows partition,
> changing directory to the location
> of the Unity 2d packages and running
>
> apt-get install unity-2d-launcher_4.12.0-0ubuntu1_i386.deb
> or
> apt-get install unity-2d-launcher
>
> returned
>
> W: Not using locking for read only lock file /var/lib/dpkg/lock
> E: Unable to write to /var/cache/apt/
> E: The package lists or status file could not be parsed or opened.
>
> What am I omitting or doing wrong?

Hey,
those lockfile errors mean you're missing "sudo"

But also when installing a deb file manually, you need to use

sudo dpkg -i filename.deb

However if you can boot to a command prompt at all, and are using wired 
connection, try

sudo apt-get install unity-2d

which should get you going. Note that you need to select "Ubuntu2D" in 
the login screen to actually
boot to it. This option is hidden under the "cog" to the right of the 
password prompt.
-G