Add local Windows Server inventory collection and validation; include core package

samsara/core/startup.py

@@ -0,0 +1,20 @@
+"""Check common desktop prerequisites before Qt can abort the process."""
+import ctypes
+import os
+import sys
+
+
+def desktop_error():
+    if not sys.platform.startswith('linux'):
+        return None
+    backend = os.environ.get('QT_QPA_PLATFORM', '').split(':')[0]
+    uses_xcb = backend == 'xcb' or (not backend and os.environ.get('DISPLAY') and not os.environ.get('WAYLAND_DISPLAY'))
+    if uses_xcb:
+        try:
+            ctypes.CDLL('libxcb-cursor.so.0')
+        except OSError:
+            return ('Samsara needs the Qt X11 cursor library. On Debian-based desktops run:\n'
+                    '  sudo apt install libxcb-cursor0\n'
+                    'Then retry: python -m samsara.main\n'
+                    'For other Linux distributions install the package providing libxcb-cursor.so.0.')
+    return None