Add workaround for missing QtCore with PyInstaller

See https://github.com/pyinstaller/pyinstaller/issues/4293
and 0abf8e7363

qutebrowser/misc/earlyinit.py

@@ -29,6 +29,7 @@ try:
 except ImportError:
     hunter = None
 
+import os
 import sys
 import faulthandler
 import traceback
@@ -130,6 +131,18 @@ def init_faulthandler(fileobj=sys.__stderr__):
         # pylint: enable=no-member,useless-suppression
 
 
+def pyinstaller_qt_workaround():
+    """Work around PATH issues with PyInstaller.
+
+    See https://github.com/pyinstaller/pyinstaller/issues/4293
+    and https://github.com/gridsync/gridsync/pull/236/commits/0abf8e7363cc8c2a10a0263e6dcceb3be1c07022
+    """
+    if (hasattr(sys, 'frozen') and
+            hasattr(sys, '_MEIPASS') and
+            sys.platform == 'win32'):
+        os.environ['PATH'] += os.pathsep + sys._MEIPASS
+
+
 def check_pyqt_core():
     """Check if PyQt core is installed."""
     try:
@@ -288,6 +301,7 @@ def early_init(args):
     init_faulthandler()
     # Here we check if QtCore is available, and if not, print a message to the
     # console or via Tk.
+    pyinstaller_qt_workaround()
     check_pyqt_core()
     # Init logging as early as possible
     init_log(args)