Handle OSError in :config-write-py

qutebrowser/config/configcommands.py

@@ -289,4 +289,7 @@ class ConfigCommands:
 
         writer = configfiles.ConfigPyWriter(options, bindings,
                                             commented=commented)
-        writer.write(filename)
+        try:
+            writer.write(filename)
+        except OSError as e:
+            raise cmdexc.CommandError(str(e))

tests/unit/config/test_configcommands.py

@@ -413,6 +413,11 @@ class TestWritePy:
         lines = confpy.read_text('utf-8').splitlines()
         assert '# Autogenerated config.py' in lines
 
+    def test_oserror(self, commands, tmpdir):
+        """Test writing to a directory which does not exist."""
+        with pytest.raises(cmdexc.CommandError):
+            commands.config_write_py(str(tmpdir / 'foo' / 'config.py'))
+
 
 class TestBind: