How to Install Unity Tweak Tool on Ubuntu: A Troubleshooting Guide

Unity Tweak Tool is a powerful customization utility for the Unity desktop environment in Ubuntu. It allows users to adjust various settings, from appearance tweaks to window manager behavior. However, installing Unity Tweak Tool can sometimes be problematic due to dependency conflicts or broken packages. This guide will walk you through the process of installing Unity Tweak Tool and troubleshoot common installation errors.

The most straightforward method to install Unity Tweak Tool is using the apt-get package manager. Open your terminal and enter the following command:

sudo apt-get install unity-tweak-tool

This command should initiate the installation process by fetching the necessary packages and their dependencies. However, you might encounter errors during this stage, as illustrated in the original user’s experience:

atenagm@atenagm-K46CB:~$ sudo apt-get install unity-tweak-tool
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 unity-tweak-tool : Depends: unity-webapps-common but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

If you encounter a similar “unmet dependencies” error, particularly concerning unity-webapps-common, it indicates that your system’s package dependencies are not correctly resolved. Here are steps to troubleshoot this:

1. Update and Fix Broken Packages:

First, ensure your package lists are up-to-date and attempt to fix any broken packages. Run these commands sequentially:

sudo apt-get update
sudo apt-get -f install

sudo apt-get update refreshes the package lists, ensuring you have the latest information on available packages and their versions. sudo apt-get -f install attempts to fix broken dependencies by trying to complete or correct any interrupted installations.

2. Check for Held Packages:

The error message “Unable to correct problems, you have held broken packages” suggests that some packages might be held back from installation or upgrade. You can check for held packages using:

dpkg --get-selections | grep hold

If any packages are listed as “hold”, you can unhold them using sudo apt-mark unhold <package_name> and then retry the installation.

3. Investigate PPA Conflicts:

Personal Package Archives (PPAs) can sometimes lead to dependency conflicts, especially if they contain packages that are newer or incompatible with your base Ubuntu system. In the original user’s case, a kubuntu-ppa/backports PPA was identified as the culprit.

If you have added PPAs, especially those related to desktop environments or Qt libraries, they might be interfering with unity-tweak-tool installation. You can list your enabled PPAs and consider temporarily disabling or removing potentially problematic ones:

• To list PPAs, you can check /etc/apt/sources.list and files in /etc/apt/sources.list.d/.
• To remove a PPA, use sudo add-apt-repository --remove ppa:<ppa_name>.

4. Using gdebi Package Installer (Alternative Method):

While apt-get is generally recommended, you can try using gdebi, a tool for installing local .deb packages, which sometimes handles dependencies differently. First, download the .deb package for unity-tweak-tool from a trusted source like packages.ubuntu.com. Then, use gdebi:

sudo gdebi <path_to_unity-tweak-tool.deb>

However, as the original user found, gdebi might also fail if the core dependency issues persist:

atenagm@atenagm-K46CB:~$ sudo gdebi unity-tweak-tool_0.0.7ubuntu2_all.deb
Reading package lists... Done
Building dependency tree
Reading state information... Done
Reading state information... Done
This package is uninstallable
Cannot install 'unity-webapps-common'

This error reinforces that the underlying issue is likely a dependency problem at the system level, not specific to the installation method.

Resolving PPA Interference (Example):

If you suspect a PPA is causing conflicts, you can try removing it. For example, if kubuntu-ppa/backports is the problem, you would remove it using:

sudo add-apt-repository --remove ppa:kubuntu-ppa/backports
sudo apt-get update
sudo apt-get install unity-tweak-tool

After removing the problematic PPA and updating the package lists, retry installing unity-tweak-tool with apt-get.

Conclusion:

Installing Unity Tweak Tool on Ubuntu is usually straightforward. However, dependency conflicts, often caused by PPAs or broken packages, can disrupt the process. By updating your system, fixing broken packages, investigating PPA conflicts, and potentially removing problematic PPAs, you can resolve most installation issues and successfully install Unity Tweak Tool to customize your Ubuntu Unity desktop. Remember to carefully consider the implications before removing PPAs, as they might affect other installed software.