cimgui-sokol-starterkit: Hangs before window appears on Linux

Hi, I’ve used master branch Sokol (via fips) for a while with very few issues. I only recently discovered this starterkit repo, and I decided to give it a go as it sounds like it could be useful for a new project I’ve been considering. However, strangely, when I’ve tried to build and run a clean checkout of the repo, it seems to hang before a window even appears. Breaking into it in the debugger seems to suggest it’s hung on the call to _sapp.glx.QueryExtensionsString(_sapp.x11.display, _sapp.x11.screen) in _sapp_glx_init(). Do you have any thoughts on what might be happening here? Is there any additional diagnostics debugging I could turn on that might help?

Not sure if useful, but here’s some gfx hardware info about my system:

$ glxinfo 
name of display: :0
display: :0  screen: 0
direct rendering: Yes
server glx vendor string: SGI
server glx version string: 1.4
client glx vendor string: Mesa Project and SGI
client glx version string: 1.4
GLX version: 1.4
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Intel (0x8086)
    Device: Mesa Intel(R) UHD Graphics 620 (KBL GT2) (0x5917)
    Version: 20.0.8
    Accelerated: yes
    Video memory: 3072MB
    Unified memory: yes
    Preferred profile: core (0x1)
    Max core profile version: 4.6
    Max compat profile version: 4.6
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.2
OpenGL vendor string: Intel
OpenGL renderer string: Mesa Intel(R) UHD Graphics 620 (KBL GT2)
OpenGL core profile version string: 4.6 (Core Profile) Mesa 20.0.8
OpenGL core profile shading language version string: 4.60
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile

And about my system:

CPU: Intel i7-8550U (8) @ 4.000GHz
GPU: Intel UHD Graphics 620
Resolution: 1920x1080
OS: Ubuntu 20.04.1 LTS x86_64
Kernel: 5.4.0-54-generic
Shell: bash 5.0.17
DE: GNOME 3.36.4
WM: Mutter

Thanks!