This article helps affected users in reporting of Firefox and Thunderbird bugs and ease package maintainers fixing them.
Using Mozilla crash reporter
Application crash can occur during runtime. Application window simply disappear and bug report dialog will show up. By accepting this dialog crash will be reported to Mozilla crashstat servers. To view and submit the crash info please do:
- Open about:crashes page
- If there is any crash report, submit them (the 'Submit All' button).
- Paste all crash ID to bugreport.
Using local debugging
Installing debug info packages
Debug info packages which contains source files are required to create meaningful bug report (unless you use Mozilla crash reporter). To install them you need to execute following command as root:
debuginfo-install firefox
for Firefox,
debuginfo-install thunderbird
for Thunderbird.
Using coredumpctl to get backtrace
You can use coredumpctl to get backtrace. Run on terminal:
coredumpctl list
and find Firefox crash there and get crash ID. Then launch gdb on it by
coredumpctl debug ID
you should get a gdb session and you should be able to get backtrace by
thread apply all bt full
gdb command.
Running application in debugger
To run application in gnu debugger you need to run command:
firefox -g -d gdb
for Firefox,
thunderbird -g -d gdb
After debugger is started which is indicated by line:
(gdb)
To run program use command:
run
Obtain crash stack trace
Then bring application to crash. This should be indicated by (gdb) prompt. Type:
set logging on crash_bt.log thread apply all bt full print DumpJSStack() set logging off
to store stack and Javascript trace into crash_bt.log file. Don't forget to attach this file to bug report.
Application freeze
If you are able to reproduce freeze you can follow #Application crash steps. There is only one difference in #Obtain crash stack trace section where (gdb) prompt is missing. To get prompt you have to press Ctrl-C.
Getting Mozilla crash report from running application
You can kill running application by kill signal and then obtain and submit Mozilla crash stats.
To terminate all firefox instances run on terminal:
kill -s 11 pidof firefox
This should terminate all Firefox instances and produce Mozilla crash report dialog. In next Firefox run you should see crash ID at about:crashes page. Please submit the crash to Mozilla and paste crash ID to bugreport.
Attach debugger to running application
Before you can attach to running application you need to have debug symbols installed.
When the freeze occurs randomly and/or difficult to predict you can attach to running application when it freezes by:
gdb firefox `ps ax|grep firefox/firefox|grep -v grep|grep -v "contentproc"|cut -d ' ' -f3`
for Firefox.
gdb thunderbird `ps ax|grep thunderbird/thunderbird|grep -v grep|grep -v "contentproc"|cut -d ' ' -f3`
for Thunderbird.
Then you can continue by #Obtain crash stack trace
Figuring out what is responsible for crash
Some crashes and problems come from installed addons or 3rd party plugins. To determine if that's the case run application with -safe-mode parameter:
firefox -safe-mode
or
thunderbird -safe-mode
Then Disable all add-ons
needs to be checked and Make Changes and Restart
pressed.
If problem still persist it isn't most likely related to addons or plugins and you can just simply follow instructions in #Application crash. Otherwise continue to next section.
Reporting addons and plugins issues
For Firefox set your location to about:plugins page. This page contains information about all installed plugins and it may help us in resolving your issue. Save it by File/Save Page As... to file and attach saved file to bug report.
For Thunderbird make screenshot of Tools/Addons/Extensions and Tools/Addons/Plugins, dialogs and attach images to bugzilla.
Attach also output of following commands:
rpm -q firefox xulrunner thunderbird flash-plugin gnash google-talkplugin nspluginwrapper thunderbird-lightning thunderbird-enigmail flash-plugin ls -l /usr/lib64/mozilla/plugins/ ls -l /usr/lib/mozilla/plugins/ ls -l /usr/share/mozilla/extensions
You may also run Firefox or Thunderbird by strace. This help us to track which dynamic libraries are loaded during startup. Strace usage:
strace firefox &> strace_output
or in case of Thunderbird:
strace thunderbird &> strace_output
and don't forget to attach created strace_output file to bug report. If application crash or freeze stack trace is also very useful, for instructions see #Application crash section.
Bug report attachment in a nutshell
To make long story short, execute following commands and attach ~/bug-report file to bugzilla:
rpm -q firefox xulrunner thunderbird flash-plugin gnash google-talkplugin nspluginwrapper thunderbird-lightning thunderbird-enigmail flash-plugin > ~/bug-report ls -l /usr/lib64/mozilla/plugins/ >> ~/bug-report ls -l /usr/lib/mozilla/plugins/ >> ~/bug-report ls -l /usr/share/mozilla/extensions >> ~/bug-report
For Firefox go to about:support and about:plugins pages, save them and attach to bug report.
For Thunderbird make screenshot of Tools/Addons/Extensions and Tools/Addons/Plugins, dialogs and attach images to bugzilla.
Continue in #Application crash if required.
Advanced debugging
TODO
Thanks for your time you spare to reporting bugs!