Segmentation fault on wayland

[Mario Geiger]

When I log on wayland, synapse does not start.
If I try to run it from the terminal then is crash.

~ synapse
[INFO 16:16:08.377679] [synapse-main:266] Starting up...
[INFO 16:16:08.457081] [synapse-main:208] Binding activation to <Alt>space
[1] 2638 segmentation fault synapse

[mirek (bletvaska)]

same with me on fedora 24

[IBBoard (ibboard)]

Same on openSUSE Tumbleweed. Crash and backtrace with debug symbols is:

Thread 1 "synapse" received signal SIGSEGV, Segmentation fault.
_XkbGetGetMapReq (dpy=dpy@entry=0x71aa60, xkb=<optimized out>) at XKBGetMap.c:477
477 XKBGetMap.c: No such file or directory.
(gdb) backtrace
#0 _XkbGetGetMapReq (dpy=dpy@entry=0x71aa60, xkb=<optimized out>) at XKBGetMap.c:477
#1 0x00007ffff463a114 in XkbGetUpdatedMap (dpy=0x71aa60, which=7, xkb=0x9a5320) at XKBGetMap.c:582
#2 0x00007ffff463a1dd in XkbGetMap (dpy=0x71aa60, which=which@entry=7, deviceSpec=deviceSpec@entry=256) at XKBGetMap.c:603
#3 0x00007ffff76e3747 in grab_ungrab (rootwin=rootwin@entry=0x732010, keyval=32, modifiers=4, grab=grab@entry=1) at bind.c:203
#4 0x00007ffff76e3885 in do_grab_key (binding=binding@entry=0x90ae50) at bind.c:326
#5 0x00007ffff76e3c60 in keybinder_bind_full (keystring=0xa4ef50 "<Control>space",
    handler=handler@entry=0x4158c0 <_synapse_ui_launcher_handle_shortcut_keybinder_handler>, user_data=user_data@entry=0x7a26e0,
    notify=notify@entry=0x0) at bind.c:586
#6 0x00007ffff76e3cb7 in keybinder_bind (keystring=<optimized out>,
    handler=handler@entry=0x4158c0 <_synapse_ui_launcher_handle_shortcut_keybinder_handler>, user_data=user_data@entry=0x7a26e0) at bind.c:551
#7 0x0000000000415423 in synapse_ui_launcher_bind_keyboard_shortcut (self=0x7a26e0)
    at /usr/src/debug/synapse-0.2.99.2/src/ui/synapse-main.vala:210
#8 synapse_ui_launcher_construct (object_type=<optimized out>) at /usr/src/debug/synapse-0.2.99.2/src/ui/synapse-main.vala:63
#9 0x0000000000415c7c in synapse_ui_launcher_new () at /usr/src/debug/synapse-0.2.99.2/src/ui/synapse-main.vala:51
#10 synapse_ui_launcher_main (argv=<optimized out>, argv_length1=<optimized out>) at /usr/src/debug/synapse-0.2.99.2/src/ui/synapse-main.vala:293
#11 0x00007ffff4907291 in __libc_start_main () from /lib64/libc.so.6
#12 0x0000000000414d0a in _start () at ../sysdeps/x86_64/start.S:120

Apparently this is because of Synapse assuming it'll be an X11 GDK display, when that is just one implementation (since now there's Wayland)

[Waldir Leoncio (wleoncio)]

I'm also on Fedora 24, but my segfault message is slightly different. For what it's worth:

"Segmentation fault (core dump creato)"

[Stuart Mumford (cadair)]

I get the same under Arch Linux on both Gnome 3.21, 3.22 and sway.

[INFO 10:27:34.995659] [synapse-main:266] Starting up...
[INFO 10:27:35.133164] [synapse-main:208] Binding activation to <Alt>space
[1] 9296 segmentation fault (core dumped) synapse

[Waldir Leoncio (wleoncio)]

Fedora 25 uses GNOME Shell 3.22 and Wayland by default, so this is going to start breaking for a lot of users. How about we raise its importance?

[Andrei Petcu (andreicristianpetcu)]

I have this issue also with Fedora 25 and Xorg by default :(

[Christopher Lee Murray (iamthinkking)]

It's solvable., I posted about it here:

https://iamthinkking.github.io/2017/01/10/Fedora25-Synapse-and-Your-Display-Server.html

**SOLUTION**
I figured it was synapse trying to access memory or a stream that doesn't exist. So I checked `synapse -h` to see what options are available. One of the options available to use `--display`. You can get synapse to successfully start by the following steps.

 1. check the location of the displays you have available: `cd /tmp/.X11-unix && for x in X*; do echo ":${x#X}"; done`
 2. then, from the locations listed, try using any as arguments to the `--display` option.

For me, `synapse --display=:0` worked just fine.

NB: This allows you to manually launch synapse. However, you MAY want to ensure that:

 1. When you start synapse from the application menu it launches with the options you desire.

    > append ` --display=:0` to the end of `Exec=synapse` in the file `/usr/share/applications/synapse.desktop`.
    > You WILL need **sudo** access to do this. *Be mindful of the space in the string you will be appending.*

 2. If it's autostarted from your startup it is launched with the options you desire.
    > ensure you have **GNOME Tweak Tool** installed. *Install it using `sudo dnf install gnome-tweak-tool` or install it from the **Software** application*. Then navigate: Tweak Tool>Startup Applications>➕. Search for Synapse then click "Add".

This should suffice as a solution until a patch is made.