Fix starting with Python 2

Fixes #2567

qutebrowser/qutebrowser.py

@@ -23,7 +23,6 @@ import sys
 import json
 
 import qutebrowser
-from qutebrowser.utils import log
 try:
     from qutebrowser.misc.checkpyver import check_python_version
 except ImportError:
@@ -38,6 +37,7 @@ except ImportError:
         sys.stderr.flush()
         sys.exit(100)
 check_python_version()
+from qutebrowser.utils import log
 
 import argparse
 from qutebrowser.misc import earlyinit
@@ -130,7 +130,7 @@ def directory(arg):
         raise argparse.ArgumentTypeError("Invalid empty value")
 
 
-def logfilter_error(logfilter: str):
+def logfilter_error(logfilter):
     """Validate logger names passed to --logfilter.
 
     Args:

tests/end2end/test_invocations.py

@@ -19,6 +19,7 @@
 
 """Test starting qutebrowser with special arguments/environments."""
 
+import subprocess
 import socket
 import sys
 import logging
@@ -254,3 +255,15 @@ def test_command_on_start(request, quteproc_new):
     quteproc_new.start(args)
     quteproc_new.send_cmd(':quit')
     quteproc_new.wait_for_quit()
+
+
+def test_launching_with_python2():
+    try:
+        proc = subprocess.Popen(['python2', '-m', 'qutebrowser',
+                                '--no-err-windows'], stderr=subprocess.PIPE)
+    except FileNotFoundError:
+        pytest.skip("python2 not found")
+    _stdout, stderr = proc.communicate()
+    assert proc.returncode == 1
+    error = "At least Python 3.4 is required to run qutebrowser"
+    assert stderr.decode('ascii').startswith(error)