140 lines
3.9 KiB
Plaintext
140 lines
3.9 KiB
Plaintext
Getting stacktraces on crashes
|
|
==============================
|
|
The Compiler <mail@qutebrowser.org>
|
|
|
|
When there is a fatal crash in qutebrowser - most of the times a
|
|
https://en.wikipedia.org/wiki/Segmentation_fault[segfault] - the crash report
|
|
usually doesn't contain much viable information, as these crashes usually
|
|
happen inside of the Qt mainloop in C++.
|
|
|
|
To know what the issue is, a
|
|
https://en.wikipedia.org/wiki/Stack_trace[stack trace] with
|
|
https://en.wikipedia.org/wiki/Debug_symbol[debugging symbols] is required.
|
|
|
|
The rest of this guide is quite Linux specific, though there is a
|
|
<<windows,section for Windows>> at the end.
|
|
|
|
Getting debugging symbols
|
|
-------------------------
|
|
|
|
.Debian/Ubuntu/...
|
|
|
|
For Debian based systems (Debian, Ubuntu, Linux Mint, ...), debug information
|
|
is available in the repositories:
|
|
|
|
----
|
|
# apt-get install python3-pyqt5-dbg python3-pyqt5.qtwebkit-dbg python3-dbg libqt5webkit5-dbg
|
|
----
|
|
|
|
.Archlinux
|
|
|
|
For Archlinux, no debug informations are provided. You can either compile Qt
|
|
yourself (which will take a few hours even on a modern machine) or use
|
|
debugging symbols compiled by me (x86_64 only).
|
|
|
|
To compile by yourself:
|
|
|
|
----
|
|
$ git clone https://github.com/The-Compiler/qt-debug-pkgbuild.git
|
|
$ cd qt-debug-pkgbuild
|
|
$ git checkout symbols
|
|
$ cd qt5
|
|
$ makepkg -si
|
|
$ cd ../pyqt5
|
|
$ makepkg -si
|
|
----
|
|
|
|
To install my pre-built packages:
|
|
|
|
----
|
|
$ mkdir qt-debug
|
|
$ cd qt-debug
|
|
$ wget -r -l1 -A '*.tar.xz' -L -np -nd http://www.qutebrowser.org/qt-symbols-pkg/
|
|
# pacman -U *.pkg.tar.xz
|
|
----
|
|
|
|
After you are done debugging, make sure to install the system packages again so
|
|
you get updates. This can be done with this command:
|
|
|
|
----
|
|
# pacman -S qt5
|
|
----
|
|
|
|
Getting a core dump
|
|
-------------------
|
|
|
|
The next step is finding the core dump so we can get a stacktrace from it.
|
|
|
|
First of all, try to reproduce your problem. If you can, run qutebrowser
|
|
directly inside gdb like this:
|
|
|
|
----
|
|
$ gdb $(which python3) -ex 'run -m qutebrowser --debug'
|
|
----
|
|
|
|
If you cannot reproduce the problem, you need to check if a coredump got
|
|
written somewhere.
|
|
|
|
Check the file `/proc/sys/kernel/core_pattern` on your system. If it does not
|
|
start with a `|` character (pipe), check if there is a file named `core` or
|
|
`core.NNNN` in the directory from that file, or in the current directory.
|
|
|
|
If so, execute gdb like this:
|
|
|
|
----
|
|
$ gdb $(which python3) /path/to/core
|
|
----
|
|
|
|
If your `/proc/sys/kernel/core_pattern` contains something like
|
|
`|/usr/lib/systemd/systemd-coredump`, use `coredumpctl` as root to run gdb:
|
|
|
|
----
|
|
# coredumpctl gdb $(which python3)
|
|
----
|
|
|
|
Getting a stack trace
|
|
---------------------
|
|
|
|
Regardless of the way you used to open gdb, you should now see something like:
|
|
|
|
----
|
|
Program received signal SIGSEGV, Segmentation fault.
|
|
...
|
|
(gdb)
|
|
----
|
|
|
|
Now enter these commands at the gdb prompt:
|
|
|
|
----
|
|
(gdb) set logging on
|
|
(gdb) set logging redirect on
|
|
(gdb) bt
|
|
# you might have to press enter a few times until you get the prompt back
|
|
(gdb) set logging redirect off
|
|
(gdb) quit
|
|
----
|
|
|
|
Now copy the last few lines of the debug log (before you got the gdb prompt)
|
|
and the full content of `gdb.txt` into the bug report. Please also add some
|
|
words about what you were doing (or what pages you visited) before the crash
|
|
happened.
|
|
|
|
[[windows]]
|
|
For Windows
|
|
-----------
|
|
|
|
When you see the _qutebrowser.exe has stopped working_ window, do not click
|
|
"Close the program". Instead, open your task manager, there right-click on
|
|
`qutebrowser.exe` and select "Create dump file". Remember the path of the dump
|
|
file displayed there.
|
|
|
|
Now install
|
|
http://www.microsoft.com/en-us/download/details.aspx?id=42933[DebugDiag] from
|
|
Microsoft, then run the "DebugDiag 2 Analysis" tool. There, check
|
|
"CrashHangAnalysis" and add your crash dump via "Add Data files". Then click
|
|
"Start analysis".
|
|
|
|
Close the Internet Explorer which opens when it's done and use the
|
|
folder-button at the top left to get to the reports. There find the report file
|
|
and send it to mail@qutebrowser.org.
|