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This document describes how to install debug packages on Ubuntu, which will aid in providing information for bugs.

Gutsy Gibbon 7.10 , Hardy Heron 8.04 and Intrepid Ibex 8.10

Use this section only if you are using Ubuntu Gutsy 7.10 , Hardy 8.04 or Intrepid Ibex. See the following section if you are using a prior version.

1. Add the following lines to /etc/apt/sources.list: (of course, replace hardy with feisty if you're using 7.04 or gutsy for 7.10)

• deb http://ddebs.ubuntu.com intrepid main universe
  deb http://ddebs.ubuntu.com intrepid-updates main universe
  deb http://ddebs.ubuntu.com intrepid-proposed main universe
  deb http://ddebs.ubuntu.com intrepid-security main universe

You may also add these lines using the Synaptic Package Manager:

a. Choose Synaptic via the System > Administration menu.

b. Choose Software Sources via the Settings menu, and click on the Third-Party Software tab.

c. Click the Add button and enter each deb ... line as above one by one and click the Add Source button (you will have to add these lines one at a time).

d. Click the Reload button once you are done adding all the deb lines.

2. Then run

• sudo apt-get update

to update your package list.

3. The debug symbol packages have the '-dbgsym' suffix attached, so to install the debug symbols for the package 'yelp', you run:

• dpkg -l yelp

Note the version number installed, e.g. 2.22.1-0ubuntu2.8.04.1, then run:

• sudo apt-get install yelp-dbgsym=2.22.1-0ubuntu2.8.04.1

Alternatively, main Ubuntu repositories could contain '-dbg' debug symbol packages. Those are equivalent to '-dbgsym'. You could use the one you want, but not both.

1. Now you make a Backtrace.

2. You can also run Valgrind, if the program crashes with a "Segmentation fault" or "Bus error".

3. Optionally, you may be asked to produce an Strace.

4. You can also provide this file : ~/.xsession-errors

References

• Announcement: https://lists.ubuntu.com/archives/ubuntu-devel-announce/2006-September/000195.html

Prior Ubuntu versions

Use this section if you are using an Ubuntu version prior to Gusty 7.10.

1. Check if the package has a debugging version available. In general, debugging packages will be named with a -dbg suffix

2. If not, you can generally* build one this way:

Something to keep in mind: if you would like to create a build you're going to need to have the relevant deb-src lines in your /etc/apt/sources.list

1. Install the development scripts:

   sudo apt-get install devscripts fakeroot

2. Find out to which package your program belongs to:

   dpkg --search <program> 

3. Install the build-time dependencies for the package:

   sudo apt-get build-dep <package>

4. Build .debs for debugging:

   export DEB_BUILD_OPTIONS="debug nostrip noopt"
   fakeroot apt-get source -b <package>

5. Install the needed .debs (they will be in the current working directory if the build succeeded):

   sudo debi <package>*.changes

* Most packages support the build of debugging version in this way. If this process doesn't work for a package, please open a bug against it.

The Xorg server

The X server will by default trap its own crashes and dump a stack trace in /var/log/Xorg.0.log. However, this stack trace is modified by the signal handler itself. To get a "normal" crash, which will trigger a core dump (and apport reporting), add this to your /etc/X11/xorg.conf:

Section "ServerFlags"
        Option "NoTrapSignals" "true"
EndSection

Please see DebuggingXorg for how to debug Xorg server crashes.

Info for the BugSquad

If you're trying to apport-retrace a crash report from a bug that didn't happen on the same Ubuntu release as the one you're running, do the following:

Say that you're running Gutsy and the crash happened on fiesty:

1. This will create a minimal fiesty system.

   sudo mkdir -p /chroots/edgy
   sudo debootstrap edgy /chroots/edgy/

2. Now you change into this minimal fiesty system.

   sudo chroot /chroot/edgy

3. edit /etc/apt/sources/list and all the repositories you need, especially Martin's ddeb repository.

4. apt-get update; apt-get install gdb apport

5. use apport-retrace as you're used to.

For more information on dealing with bug reports Apport see Bugs/ApportRetraces.

CategoryBugSquad CategoryDebugging