Accessing Screen.Displays[0] sometimes crash in gdk on debian 10 buster

[Mathieu]

When launching our app on debian 10 buster accessing Screen.Displays[0] usually crash the second times we try to access it (sometimes the first time, sometimes the 3rd time!).

Accessing Screen.Displays[0] on debian 9/redhat 7/ubuntu LTS works ok. Accessing Screen.Displays[1] on buster works ok.

I did try to reproduce the crash in a simple test but the bug does not appears in that case.
So this is probably related to some other portion of code in our app. But the fact that it was working ok on any other older distrib make me doubt that. Have you got any idea ? Perhaps this is related to new gdk version ?

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Here is the gdb trace :

Thread 1 "W3DClient" received signal SIGABRT, Aborted.
[Switching to Thread 0x7ffff4371a80 (LWP 2421)]
0x00007ffff7df47bb in raise () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) bt
#0 0x00007ffff7df47bb in raise () at /lib/x86_64-linux-gnu/libc.so.6
#1 0x00007ffff7ddf535 in abort () at /lib/x86_64-linux-gnu/libc.so.6
#2 0x00007ffff7ddf40f in () at /lib/x86_64-linux-gnu/libc.so.6
#3 0x00007ffff7ded102 in () at /lib/x86_64-linux-gnu/libc.so.6
#4 0x00007ffff6c342ce in _XReply () at /usr/lib/x86_64-linux-gnu/libX11.so.6
#5 0x00007ffff6c31229 in XTranslateCoordinates () at /usr/lib/x86_64-linux-gnu/libX11.so.6
#6 0x00007ffff6d9597a in () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#7 0x00007ffff6d9b978 in () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#8 0x00007ffff6d9b485 in () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#9 0x00007ffff6d65940 in gdk_display_get_event () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#10 0x00007ffff6d9b102 in () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#11 0x00007ffff7593f2e in g_main_context_dispatch () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#12 0x00007ffff75941c8 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#13 0x00007ffff75944c2 in g_main_loop_run () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#14 0x00007ffff7067b15 in gtk_main () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#15 0x00007ffff1d93659 in () at /home/msouchaud/.fmxlinux/libfmux-1.41.so
#16 0x00000000023f5a50 in ()
#17 0x0000000000000000 in ()
(gdb)

[Eugene Kryukov]

We will try to install it and check

[Mathieu]

Ok, thanks.

[Eugene Kryukov]

We’ve tested Screen.Displays at Debian 10 RC1 - works fine many times. What Delphi version do you use ?

[Mathieu]

We uses Rio 10.3.1. It crashes on debian 10 for us only when we are trying to capture display :0 at the same time.
It works on any other cases. I think I need to investigate a bit more.