How to diagnose

First check if the problem is in a Compiz dependency by upgrading your system to the latest version. Bugs in the video stack (kernel, X and mesa) may appear as Compiz problems.

Try different visual effects settings from the appearance preferences (System -> Preferences -> Appearance -> Visual Effects). If the problem still occurs with effects set to "None" then the problem is no in Compiz but one of the systems mentioned above.

If you have changed the default settings in "CompizConfig Settings Manager" (package name compizconfig-settings-manager) then try resetting these to the defaults by launching it from from System -> Preferences and clicking on the "Preferences" button and then on the "Reset to defaults" button.

For bugs related to Unity please have a look to Unity/FilingBugs

How to file

If you have confirmed the bug appears to be in compiz file it using the following command:

ubuntu-bug compiz

This ensures that all appropriate information about your system is automatically attached to the bug report.

Please attach screenshots showing the problem in detail.

Describe what occurred and what you expected should have occurred.

Indicate if the problem is repeatable and what steps cause it.

Indicate if there is a workaround to the problem.

Example:

FancySwitcher does not show all windows.

To reproduce:
1. Log in
2. Open three GEdit windows
3. Press meta-tab

What occurs:
Only 2 windows are shown in switcher (see attached screenshot with annotations)

What was expected:
All three GEdit windows would be shown in the switcher as occurs when using the standard switcher (alt-tab).

Advanced Debugging

Getting a Backtrace

Install the debugging symbol packages (see DebuggingProgramCrash for how to add the debug repository):

sudo apt-get install compiz-core-dbgsym compiz-plugins-default-dbgsym compiz-gnome-dbgsym libcompizconfig0-dbgsym libdecoration0-dbgsym

run gdb as: 
$ gdb --args compiz --replace
...
(gdb) set logging on compiz-crash.txt
(gdb) run
...
(once it crashes)
...
(gdb) thread apply all bt full
(gdb) set logging off

Then you can attach that resulting log file (compiz-crash.txt) to the bug report.

Stale crashers

If apport did not automatically report the issue, you can check that a crasher trace has been collected by looking into the /var/crash directory. You should see a filename containing 'compiz'.

ls -altr /var/crash to list them in chronological order.

To manually file a bug report using a crash file:

• stay in your current X session

• add a window manager from a TTY if needed, ie CTRL-ALT-F1, login, DISPLAY=:0 metacity --replace

• then, from your X session, do: apport-bug -c /var/crash/<compiz crash file> and follow the procedure in the web page that should open shortly after you invoke this command. Note that focus issues may prevent the page to appear on the top, but look for a new browser window opened in your workspace.

CategoryBugSquad CategoryDebugging