This document describes how to debug i3 suitably for sending us useful bug -reports, even if you have no clue of C programming.
First of all: Thank you for being interested in debugging i3. It really means +
This document describes how to debug i3 to send us useful bug +reports, even if you have no knowledge of C programming.
Thank you for being interested in debugging i3. It really means something to us to get your bug fixed. If you have any questions about the -debugging and/or need further help, do not hesitate to contact us!
1. Enabling logging
+1. Verify you are using i3 ⥠4.12
i3 logs useful information to stdout. To have a clearly defined place where log -files will be saved, you should redirect stdout and stderr in your -~/.xsession. While youâre at it, putting each run of i3 in a separate log -file with date/time in its filename is a good idea to not get confused about -the different log files later on.
Only the latest major version of i3 is supported. To verify which version +you are running, use:
exec /usr/bin/i3 >~/i3log-$(date +'%F-%k-%M-%S') 2>&1-
To enable verbose output and all levels of debug output (required when -attaching logfiles to bugreports), add the parameters -V -d all, like this:
exec /usr/bin/i3 -V -d all >~/i3log-$(date +'%F-%k-%M-%S') 2>&1+
$ i3 --moreversion 2>&- || i3 --version +Binary i3 version: 4.7 (2013-12-22, branch "tags/4.7") +Running i3 version: 4.7-84-gac74a63 (2014-01-01, branch "next") (pid 1995)
Your version can look like this:
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+
- +4.7 (release version) + +
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+
+You are using a release version. In many cases, bugs are already +fixed in the development version of i3. Even if the bug is not a known fixed +one, we will still ask you to reproduce your error with the most recent +development version of i3. Therefore, please upgrade to a development version +if you can. +
+
+ - +4.7-85-g9c15b95 (development version) + +
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+
+Your version is 85 commits newer than 4.7, and the git revision of your +version is 9c15b95. Go to http://code.i3wm.org/i3/commit/?h=next and see if +the line "commit" starts with the same revision. If so, you are using the +latest version. +
+
+
Development versions of i3 have logging enabled by default and are compiled +with debug symbols.
2. Enabling core dumps
+2. Enabling logging
When i3 crashes, often you have the chance of getting a core dump (an image -of the memory of the i3 process which can be loaded into a debugger). To get a -core dump, you have to make sure that the user limit for core dump files is set -high enough. Many systems ship with a default value which even forbids core -dumps completely. To disable the limit completely and thus enable core dumps, -use the following command (in your ~/.xsession, before starting i3):
If you are using a development version (see previous section), you donât need +to do anything — skip to section 3.
If you are using a release version with a custom ~/.xsession (or xinitrc) +file, execute i3 with a line like this:
# Use 25 MiB of RAM for debug logs +exec i3 --shmlog-size=26214400+
If you are NOT using an ~/.xsession file but you just chose "i3" from the +list of sessions in your desktop manager (gdm, lxdm, â¦), edit +/usr/share/xsessions/i3.desktop and replace the Exec=i3 line with:
ulimit -c unlimited+
Exec=i3 --shmlog-size=26214400
Furthermore, to easily recognize core dumps and allow multiple of them, you -should set a custom core dump filename pattern, using a command like the -following:
If you cannot restart i3 for some reason, you can enable debug logging on the +fly:
sudo sysctl -w kernel.core_pattern=core.%e.%p+
i3-msg 'debuglog on; shmlog on; reload'
This will generate files which have the executableâs file name (%e) and the -process id (%p) in it. You can save this setting across reboots using -/etc/sysctl.conf.
3. Compiling with debug symbols
+3. Reproducing the problem
To actually get useful core dumps, you should make sure that your version of i3 -is compiled with debug symbols, that is, that the symbols are not stripped -during the build process. You can check whether your executable contains -symbols by issuing the following command:
file $(which i3)-
You should get an output like this:
/usr/bin/i3: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically -linked (uses shared libs), for GNU/Linux 2.6.18, not stripped-
Notice the not stripped, which is the important part. If you have a version -which is stripped, please have a look if your distribution provides debug -symbols (package i3-wm-dbg on Debian for example) or if you can turn off -stripping. If nothing helps, please build i3 from source.
Before submitting an issue, please make sure to close down on the problem as +much as you can yourself. Here are some steps you should consider:
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+
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+Find a deterministic, reliable way to reproduce the problem and provide it + with your bug report. +
+
+ -
+
+Try using the default i3 config to reproduce the problem. If the issue does + not appear with the default config, gradually adapt it to track down what + change(s) to the config introduce the problem. +
+
+ -
+
+Reproduce the problem with a minimal setup, i.e., only use as few applications, + windows and steps as necessary. +
+
+ -
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+In addition, try to stick to applications that are common and, even more + importantly, free / open source. +
+
+ -
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+Before obtaining the log file, restart i3 in-place, execute the steps to + reproduce the problem and then save the logs. This keeps the log file as + small as possible and necessary. +
+
+
Please be aware that we cannot support compatibility issues with closed-source +software, as digging into compatibility problems without having access to the +source code is too time-consuming. Additionally, experience has shown that +often, the software in question is responsible for the issue. Please raise an +issue with the software in question, not i3.
4. Generating a backtrace
+4. Obtaining the debug logfile
Once you have made sure that your i3 is compiled with debug symbols and that -core dumps are enabled, you can start making sense out of the core dumps.
Because the core dump depends on the original executable (and its debug -symbols), please do this as soon as you encounter the problem. If you -re-compile i3, your core dump might be useless afterwards.
Please install gdb, a debugger for C. No worries, you donât need to learn it -now. Start gdb using the following command (replacing the actual name of the -core dump of course):
|
+ Caution
+ |
+
+ Logs may contain sensitive information, so please inspect the log before +submitting it. Logs may be viewed by anyone, once posted. If you choose to +redact the log, make an effort not to discard information which may be relevant +to the issue you are reporting. The best way to avoid submitting such information is to only run the necessary +steps to reproduce the behavior when saving the log file. This will also make +analyzing the log file easier. |
+
No matter whether i3 misbehaved in some way without crashing or whether it just +crashed, the logfile provides all information necessary to debug the problem.
To upload a compressed version of the logfile (for a bugreport), use:
gdb $(which i3) core.i3.3849+
DISPLAY=:0 i3-dump-log | bzip2 -c | curl --data-binary @- http://logs.i3wm.org
Then, generate a backtrace using:
This command does not depend on i3 (it also works while i3 displays +the crash dialog), but it requires a working X11 connection.
After running it, you will get a URL to the logfile. Please include that URL in +your bug report.
5. On crashes: Obtaining a backtrace
+When i3 crashes, it will display a dialog stating âi3 just crashedâ, offering +you to save a backtrace to a text file.
To actually get useful backtraces, you should make sure that your version of i3 +is compiled with debug symbols:
backtrace full+
$ file `which i3` +/usr/bin/i3: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically +linked (uses shared libs), for GNU/Linux 2.6.18, not stripped
Notice the not stripped, which is the important part. If you have a version +which is stripped, please check whether your distribution provides debug +symbols (package i3-wm-dbg on Debian for example) or if you can turn off +stripping. If nothing helps, please build i3 from source.
Once you have made sure that your i3 is compiled with debug symbols and the C +debugger gdb is installed on your machine, you can let i3 generate a +backtrace in the crash dialog.
After pressing "b" in the crash dialog, you will get a file called +/tmp/i3-backtrace.%d.%d.txt where the first %d is replaced by i3âs process +id (PID) and the second one is incremented each time you generate a backtrace, +starting at 0.
5. Sending bug reports/debugging on IRC
+6. Sending bug reports/debugging on IRC
When sending bug reports, please paste the relevant part of the log (if in -doubt, please send us rather too much information than too less) and the whole -backtrace (if there was a core dump).
When sending bug reports, please attach the whole log file. Even if you think +you found the section which clearly highlights the problem, additional +information might be necessary to completely diagnose the problem.
When debugging with us in IRC, be prepared to use a so called nopaste service such as http://nopaste.info or http://pastebin.com because pasting large amounts of text in IRC sometimes leads to incomplete lines (servers have line length limitations) or flood kicks.
7. Debugging i3bar
+To debug i3bar problems, add verbose yes to all bar {} blocks in your i3 +config, reload your config and then restart all i3bar instances like this:
$ i3 reload
+$ killall i3bar
+$ for c in $(i3-msg -t get_bar_config | python -c \
+ 'import json,sys;print("\n".join(json.load(sys.stdin)))'); do \
+ (i3bar --bar_id=$c >i3bar.$c.log 2>&1) & \
+ done;
+There will now be i3bar.*.log files in your current directory that you can provide +in your bug report.