libinput/doc/reporting-bugs.dox

/**
@page reporting_bugs Reporting bugs

A new bug can be filed here:
https://gitlab.freedesktop.org/libinput/libinput

When reporting bugs against libinput, please follow the instructions below
and provide the required data. You will need:

- a reliable @ref reporting_bugs_reproducer "reproducer" for the bug
- an @ref evemu "evemu recording" of the device while the bug is reproduced
- device-specific information, see
	- @ref reporting_bugs_touchpad
	- @ref reporting_bugs_mouse
	- @ref reporting_bugs_keyboard
	- @ref reporting_bugs_trackpoint
	- @ref reporting_bugs_other
- the @ref reporting_bugs_version "libinput version" you are on.
- the @ref reporting_bugs_options "configuration options" you have set
- a bugzilla account

If you don't have all of the above, provide a reason why not. Unless the
reason is justified, the bug will have low priority. Remember, libinput has
a lot of users but very few developers.

Stay technical, on-topic, and keep the description concise.

@section reporting_bugs_version Obtaining the libinput version

If your libinput version is older than the current stable branch, you will
get asked to try the latest version.

If you run a distribution-provided libinput, use the package manager to get
the **full** package name and version of libinput, e.g.
- `rpm -q libinput`
- `dpkg -s libinput10`

If you run a self-compiled version of libinput provide the git commit you
have built or the tarball name.

As a last resort, use `libinput-list-devices --version`

@section reporting_bugs_reproducer Reproducing bugs

Try to identify the bug by reproducing it reliably. Bugs without a
reliable reproducer will have lowest priority. The more specific a bug
description and reproducer is, the easier it is to fix.

Try to replicate the series of events that lead to the bug being triggered.
Narrow it down until you have a reliable sequence that can trigger the bug.
For the vast majority of bugs you should not take longer than 5 seconds or
three interactions (clicks, touches, taps, ...) with the device to
reproduce. If it takes longer than that, you can narrow it down further.

Once you can reproduce it, use the @ref libinput-debug-events helper tool.
The output is textual and can help identify whether the bug is in libinput
at all. Note that any configuration options you have set must be specified
on the commandline, see the @ref libinput-debug-events
"libinput-debug-events" man page. Use the `--verbose` flag to get more
information about how libinput processes events.

If the bug cannot be reproduced with the @ref libinput-debug-events helper,
even with the correct configuration options set, it is likely not a bug in
libinput.

@section reporting_bugs_options libinput configuration settings

libinput has a number of device-specific default configuration settings that
may differ from the ones your desktop environment picks by default. You may
have changed some options in a settings panel or in an the xorg.conf snippet
yourself.

You must provide these options in the bug report, otherwise a developer
reproducing the issue may not be able to do so.

If you are on X11, the current settings can be can be obtained with
`xinput list-props "your device name"`. Use `xinput list` to
obtain the device name.

If you are on Wayland, provide a manual summary of the options you have
changed from the default (e.g. "I enabled tap-to-click").

@section reporting_bugs_touchpad Reporting touchpad bugs

When you file a bug, please attach the following information:

- a virtual description of your input device, see @ref evemu. This is the
  most important piece of information, do not forget it!
- the output from udevadm info, see @ref udev_info.
- the vendor model number of your laptop (e.g. "Lenovo Thinkpad T440s")
- and the content of `/sys/class/dmi/id/modalias`.
- run the `touchpad-edge-detectior` tool (provided by libevdev) and verify
  that the ranges and sizes it prints match the touchpad (up to 5mm
  difference is ok)

If you are reporting a bug related to button event generation:

- does your touchpad have (separate) physical hardware buttons or is the
  whole touchpad clickable?
- Are you using software buttons or clickfinger? See @ref
  clickpad_softbuttons.
- Do you have @ref tapping enabled?

@section reporting_bugs_mouse Reporting mouse bugs

When you file a bug, please attach the following information:

- a virtual description of your input device, see @ref evemu. This is the
  most important piece of information, do not forget it!
- the vendor model number of the device (e.g. "Logitech M325")
- the output from udevadm info, see @ref udev_info.

If the bug is related to the @ref motion_normalization_customization "speed of the mouse":

- the resolution of the mouse as specified by the vendor (in DPI)
- the output of the `mouse-dpi-tool` (provided by libevdev)

@section reporting_bugs_keyboard Reporting keyboard bugs

Is your bug related to a keyboard layout? libinput does not handle keyboard
layouts and merely forwards the physical key events. File the bug with your
desktop environment instead (e.g. GNOME, KDE, ...), that's most likely where
the issue is.

When you file a bug, please attach the following information:

- a virtual description of your input device, see @ref evemu. This is the
  most important piece of information, do not forget it!

@section reporting_bugs_trackpoint Reporting trackpoint bugs

When you file a bug, please attach the following information:

- a virtual description of your input device, see @ref evemu. This is the
  most important piece of information, do not forget it!
- the vendor model number of the device (e.g. "Logitech M325")
- the output from udevadm info, see @ref udev_info.
- the output of `libinput measure trackpoint-range`
- the sensitivity of the trackpoint (adjust the event node number as needed):

@verbatim
$ cat /sys/class/input/event17/device/device/sensitivity
@endverbatim

@section reporting_bugs_other All other devices

When you file a bug, please attach the following information:

- a virtual description of your input device, see @ref evemu. This is the
  most important piece of information, do not forget it!
- the vendor model number of the device (e.g. "Sony Plastation3 controller")

@section udev_info udev information for the device

In many cases, we require the udev properties assigned to the device to
verify whether device-specific quirks were applied. This can be obtained
with ````udevadm info /sys/class/input/eventX```, with the correct event
node for your device. An example output is below:

@code
$ udevadm info /sys/class/input/event4
P: /devices/platform/i8042/serio1/input/input5/event4
N: input/event4
E: DEVNAME=/dev/input/event4
E: DEVPATH=/devices/platform/i8042/serio1/input/input5/event4
E: EVDEV_ABS_00=::41
E: EVDEV_ABS_01=::37
E: EVDEV_ABS_35=::41
E: EVDEV_ABS_36=::37
E: ID_INPUT=1
E: ID_INPUT_HEIGHT_MM=66
E: ID_INPUT_TOUCHPAD=1
E: ID_INPUT_WIDTH_MM=97
E: MAJOR=13
E: MINOR=68
E: SUBSYSTEM=input
E: USEC_INITIALIZED=5463031
@endcode

@section evemu Recording devices with evemu

@note Where available, the @ref libinput-record tools should be used instead
of evemu

<a href="https://www.freedesktop.org/wiki/Evemu/">evemu</a> records the
device capabilities together with the event stream from the kernel. On our
side, this allows us to recreate a virtual device identical to your device
and re-play the event sequence, hopefully triggering the same bug.

evemu-record takes a <tt>/dev/input/eventX</tt> event node, but without arguments
it will simply show the list of devices and let you select:
@code
$ sudo evemu-record > scroll.evemu
Available devices:
/dev/input/event0:	Lid Switch
/dev/input/event1:	Sleep Button
/dev/input/event2:	Power Button
/dev/input/event3:	AT Translated Set 2 keyboard
/dev/input/event4:	SynPS/2 Synaptics TouchPad
/dev/input/event5:	Video Bus
/dev/input/event6:	ELAN Touchscreen
/dev/input/event10:	ThinkPad Extra Buttons
/dev/input/event11:	HDA Intel HDMI HDMI/DP,pcm=3
/dev/input/event12:	HDA Intel HDMI HDMI/DP,pcm=7
/dev/input/event13:	HDA Intel HDMI HDMI/DP,pcm=8
/dev/input/event14:	HDA Intel PCH Dock Mic
/dev/input/event15:	HDA Intel PCH Mic
/dev/input/event16:	HDA Intel PCH Dock Headphone
/dev/input/event17:	HDA Intel PCH Headphone
/dev/input/event18:	Integrated Camera
/dev/input/event19:	TPPS/2 IBM TrackPoint
Select the device event number [0-19]:
@endcode

Select the device that triggers the issue, then reproduce the bug and Ctrl+C
the process. The resulting recording, ("scroll.evemu" in this example) will
contain the sequence required to reproduce the bug. If the bug fails to
reproduce during recording, simply Ctrl+C and restart evemu-record.
Always start the recording from a neutral state, i.e. without any buttons or
keys down, with the position of the device in the neutral position, without
touching the screen/touchpad.

@note The longer the recording, the harder it is to identify the event
sequence triggering the bug. Please keep the event sequence as short as possible.

To verify that the recording contains the bug, you can replay it on your
device. For example, to replay the sequence recorded in the example above:
@code
$ sudo evemu-play /dev/input/event4 < scroll.evemu
@endcode

If the bug is triggered by replaying on your device, attach the recording to
the bug report.

@note libinput does not affect the evemu recording. libinput and evemu talk
directly to the kernel's device nodes. An evemu recording is not influenced
by the libinput version or whether a libinput context is currently active.

@dotfile evemu.gv

@section fixed_bugs My bug was closed as fixed, what now?

libinput's policy on closing bugs is: once the fix for a given bug is on git
master, the bug is considered fixed and the bugzilla entry will be closed
accordingly.

Of course, unless you actually run git master, the bug will continue to
affect you on your local machine. You are most likely running the
distribution's package and you will need to wait until the distribution has
updated its package accordingly.

<b>Do not re-open a bug just because it hasn't trickled down to your
distribution's package version yet.</b>

Whether the bug fix ends up in your distribution depends on a number of
things. Any given bug fix **may** be cherry-picked into the current stable
branch, depending on its severity, impact, and likelyhood to cause
regressions. Once cherry-picked it will land in the next stable branch
release. These are usually a few weeks apart.

<b>Do not re-open a bug because it wasn't picked into a stable branch
release or because your distribution didn't update to the latest stable
branch release.</b>

Stable branches are usually discontinued when the next release comes out.

Your distribution may pick a patch up immediately and ship the fix
even before the next stable branch update is released. For example, Fedora
does this frequently.

<b>If a bug needs to be fixed urgently, file a bug in your distribution's
bug tracker.</b>

Patches on git master will end up in the next libinput release. Once your
distribution updates to that release, your local libinput version will
contain the fix.

<b>Do not re-open a bug because your distribution didn't update to the
release.</b>

You can always run libinput from git master (see @ref building_libinput).
Even while in development, libinput is very stable so this option isn't as
scary as it may sounds.

@subsection reporting_bugs_reopen When is it ok to re-open a fixed bug?

Any time the bug was considered fixed but it turns out that the fix is
insufficient and/or causes a regression.

However, if the regression is in behavior unrelated to the fix itself it is
usually better to file a new bug to reduce the noise. For example, if a fix
to improve tapping breaks two-finger scrolling behavior, you should file a
new bug but reference the original bug.

*/