Comment 2 for bug 1747938

StacktraceTop:
 XQueryExtension (dpy=dpy@entry=0x5643c9019900, name=name@entry=0x7fc67a40d8d8 "XFree86-VidModeExtension", major_opcode=major_opcode@entry=0x7ffd1fe806c4, first_event=first_event@entry=0x7ffd1fe806c8, first_error=first_error@entry=0x7ffd1fe806cc) at ../../src/QuExt.c:43
 XInitExtension (dpy=dpy@entry=0x5643c9019900, name=name@entry=0x7fc67a40d8d8 "XFree86-VidModeExtension") at ../../src/InitExt.c:47
 XextAddDisplay (extinfo=0x7fc67a60f170 <_xf86vidmode_info_data>, dpy=0x5643c9019900, ext_name=ext_name@entry=0x7fc67a40d8d8 "XFree86-VidModeExtension", hooks=hooks@entry=0x7fc67a60f100 <xf86vidmode_extension_hooks>, nevents=nevents@entry=0, data=data@entry=0x0) at ../../src/extutil.c:110
 find_display (dpy=<optimized out>) at ../../src/XF86VMode.c:80
 XF86VidModeQueryExtension (dpy=<optimized out>, event_basep=event_basep@entry=0x7ffd1fe80788, error_basep=error_basep@entry=0x7ffd1fe8078c) at ../../src/XF86VMode.c:97