Updated userguide for the directive focus_on_window_activation introduced in #1426.

[i3/i3] / docs / debugging

diff --git a/docs/debugging b/docs/debugging
index b4bda6709c621dd2e3b3d442effeca92417f6f6d..1253b0c50fc2b405f8279d36211c7c02014174fd 100644 (file)
--- a/docs/debugging
+++ b/docs/debugging
@@ -1,102 +1,121 @@
 Debugging i3: How To
 ====================
 Debugging i3: How To
 ====================

-Michael Stapelberg <michael+i3@stapelberg.de>
-March 2010
+Michael Stapelberg <michael@i3wm.org>
+January 2014

 
 

-This document describes how to debug i3 suitably for sending us useful bug
-reports, even if you have no clue of C programming.
+This document describes how to debug i3 to send us useful bug
+reports, even if you have no knowledge of C programming.

 
 

-First of all: Thank you for being interested in debugging i3. It really means
+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
 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!
+process and/or need further help, do not hesitate to contact us!
+
+== Verify you are using i3 ≥ 4.7
+
+Only the latest major version of i3 is supported, i.e. version 4.7 currently.
+To verify which version you are running, use:
+
+---------------
+$ 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:
+
+4.7 (release version)::
+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)::
+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.

 
 == Enabling logging
 
 
 == Enabling logging
 

-i3 spits out much information onto stdout, if told so. To have a clearly
-defined place where log files will be saved, you should redirect stdout and
-stderr in xsession. While you’re at it, putting each run of i3 in a seperate
-log file with date/time in it is a good idea to not get confused about the
-different log files later on.
+If you are using a development version (see previous section), you don’t 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
+----------------------------------

 
 

---------------------------------------------------------------------
-exec /usr/bin/i3 -V -d all >/home/michael/i3/i3log-$(date +'%F-%k-%M-%S') 2>&1
---------------------------------------------------------------------
+If you are *NOT* using an +~/.xsession+ file but you just chose "i3" from the
+list of sessions in your desktop manager (gdm, lxdm, …), edit
++/usr/share/xsessions/i3.desktop+ and replace the +Exec=i3+ line with:

 
 

-== Enabling core dumps
+------------------------------
+Exec=i3 --shmlog-size=26214400
+------------------------------

 
 

-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 cannot restart i3 for some reason, you can enable debug logging on the
+fly:

 
 

--------------------
-ulimit -c unlimited
--------------------
+---------------------------------------
+i3-msg 'debuglog on; shmlog on; reload'
+---------------------------------------

 
 

-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:
+== Obtaining the debug logfile

 
 

----------------------------------------------
-sudo sysctl -w kernel.core_pattern=core.%e.%p
----------------------------------------------
+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.

 
 

-This will generate files which have the executable’s file name (%e) and the
-process id (%p) in it. You can save this setting across reboots using
-+/etc/sysctl.conf+.
+To upload a compressed version of the logfile (for a bugreport), use:
+------------------------------------------------------------------------------
+DISPLAY=:0 i3-dump-log | bzip2 -c | curl --data-binary @- http://logs.i3wm.org
+------------------------------------------------------------------------------
+
+This command does not depend on i3 (it also works while i3 displays
+the crash dialog), but it requires a working X11 connection.

 
 

-== Compiling with debug symbols
+After running it, you will get a URL to the logfile. Please include that URL in
+your bug report.

 
 

-To actually get useful core dumps, you should make sure that your version of i3
-is compiled with debug symbols, that is, that they are not stripped during the
-build process. You can check whether your executable contains symbols by
-issuing the following command:
+== On crashes: Obtaining a backtrace

 
 

-----------------
-file $(which i3)
-----------------
+When i3 crashes, it will display a dialog stating “i3 just crashed”, 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:

 
 

-You should get an output like this:

 ------------------------------------------------------------------------------
 ------------------------------------------------------------------------------

+$ 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
 /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
+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.
 
 symbols (package +i3-wm-dbg+ on Debian for example) or if you can turn off
 stripping. If nothing helps, please build i3 from source.
 

-== Generating a backtrace
-
-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 don’t need to learn it
-now.  Start gdb using the following command (replacing the actual name of the
-core dump of course):
-
-----------------------------
-gdb $(which i3) core.i3.3849
-----------------------------
-
-Then, generate a backtrace using:
+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.

 
 

---------------
-backtrace full
---------------
+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 i3’s process
+id (PID) and the second one is incremented each time you generate a backtrace,
+starting at 0.

 
 == Sending bug reports/debugging on IRC
 
 
 == 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
 
 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