screeninfo: is broken on X11

[sersorrel]

Describe the bug

remarkable-mouse doesn't work for me, exiting with the following traceback:

Traceback (most recent call last):
  File "/nix/store/f72ayjpqd585h98xn4dmy9lbj28ghql4-remarkable-mouse-7.0.1/bin/.remarkable-mouse-wrapped", line 9, in <module>
    sys.exit(main())
  File "/nix/store/f72ayjpqd585h98xn4dmy9lbj28ghql4-remarkable-mouse-7.0.1/lib/python3.9/site-packages/remarkable_mouse/remarkable_mouse.py", line 150, in main
    read_tablet(
  File "/nix/store/f72ayjpqd585h98xn4dmy9lbj28ghql4-remarkable-mouse-7.0.1/lib/python3.9/site-packages/remarkable_mouse/pynput.py", line 34, in read_tablet
    monitor = get_monitor(region, monitor_num, orientation)
  File "/nix/store/f72ayjpqd585h98xn4dmy9lbj28ghql4-remarkable-mouse-7.0.1/lib/python3.9/site-packages/remarkable_mouse/common.py", line 33, in get_monitor
    monitor = get_monitors()[monitor_num]
  File "/nix/store/z7651900fmyk3r0dz9il559sq3hn8lyl-screeninfo-0.8/lib/python3.9/site-packages/screeninfo/screeninfo.py", line 32, in get_monitors
    raise ScreenInfoError("No enumerators available")
screeninfo.common.ScreenInfoError: No enumerators available

Digging through github issues led me to https://github.com/rr-/screeninfo/issues/48, and the following traceback:

$ python -m screeninfo xrandr
Traceback (most recent call last):
  File "/nix/store/xpwwghl72bb7f48m51amvqiv1l25pa01-python3-3.9.13/lib/python3.9/runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/nix/store/xpwwghl72bb7f48m51amvqiv1l25pa01-python3-3.9.13/lib/python3.9/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/nix/store/z7651900fmyk3r0dz9il559sq3hn8lyl-screeninfo-0.8/lib/python3.9/site-packages/screeninfo/__main__.py", line 23, in <module>
    main()
  File "/nix/store/z7651900fmyk3r0dz9il559sq3hn8lyl-screeninfo-0.8/lib/python3.9/site-packages/screeninfo/__main__.py", line 18, in main
    for monitor in get_monitors(args.enumerator):
  File "/nix/store/z7651900fmyk3r0dz9il559sq3hn8lyl-screeninfo-0.8/lib/python3.9/site-packages/screeninfo/screeninfo.py", line 21, in get_monitors
    return list(ENUMERATOR_MAP[Enumerator(name)].enumerate_monitors())
  File "/nix/store/z7651900fmyk3r0dz9il559sq3hn8lyl-screeninfo-0.8/lib/python3.9/site-packages/screeninfo/enumerators/xrandr.py", line 65, in enumerate_monitors
    xlib = load_library("X11")
  File "/nix/store/z7651900fmyk3r0dz9il559sq3hn8lyl-screeninfo-0.8/lib/python3.9/site-packages/screeninfo/util.py", line 10, in load_library
    raise ScreenInfoError("Could not load " + name)
screeninfo.common.ScreenInfoError: Could not load X11

I guess this is a problem with screeninfo's packaging, but I'm unsure what exactly the issue is, or how to fix it; maybe related to #7307?

Steps To Reproduce

1. nix-shell -p python3Packages.screeninfo 'python3.withPackages (p: with p; [ screeninfo ])' --command "python -m screeninfo xrandr"

Expected behavior

screeninfo (and, by extension, remarkable-mouse) should work.

Notify maintainers

@NickHu

Metadata

$ nix-shell -p nix-info --run "nix-info -m"
 - system: `"x86_64-linux"`
 - host os: `Linux 5.15.59, NixOS, 22.05 (Quokka), 22.05.20220810.e4c9d95`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.8.1`
 - channels(ash): `""`
 - channels(root): `""`
 - nixpkgs: `/etc/nixpkgs/channels/nixpkgs`

[raphaelr]

As far as I know there is no infrastructure in place that lets find_library("X11") (in util.py) work correctly, since it has no knowledge about the Nix store or the buildInputs of screeninfo.

There used to be a substituteInPlace call which replaced all find_library calls with store paths, but it was removed in e9120ab. I think the two load_library related substitutions need to be added back in (compare with nextcord, which contains comparable code).

[sersorrel]

Replacing find_library() calls seems sensible, I will try to make a PR.

A workaround for now (e.g. for remarkable-mouse users) is to set $LD_LIBRARY_PATH to ${xorg.libX11}/lib:${xorg.libXinerama}/lib:${xorg.libXrandr}/lib, but that probably isn't usable within the library itself.