Log executed command for GUIProcess.

See #797.

qutebrowser/misc/guiprocess.py

@@ -125,8 +125,9 @@ class GUIProcess(QObject):
             raise ValueError("Trying to start a running QProcess!")
         self.cmd = cmd
         self.args = args
+        fake_cmdline = ' '.join(shlex.quote(e) for e in [cmd] + list(args))
+        log.procs.debug("Executing: {}".format(fake_cmdline))
         if self.verbose:
-            fake_cmdline = ' '.join(shlex.quote(e) for e in [cmd] + list(args))
             message.info(self._win_id, 'Executing: ' + fake_cmdline)
 
     def start(self, cmd, args, mode=None):

tests/unit/misc/test_guiprocess.py

@@ -176,6 +176,17 @@ def test_cmd_args(fake_proc):
     assert (fake_proc.cmd, fake_proc.args) == (cmd, args)
 
 
+def test_start_logging(fake_proc, caplog):
+    """Make sure that starting logs the executed commandline."""
+    cmd = 'does_not_exist'
+    args = ['arg', 'arg with spaces']
+    with caplog.atLevel(logging.DEBUG):
+        fake_proc.start(cmd, args)
+    msgs = [e.msg for e in caplog.records()]
+    assert msgs == ["Starting process.",
+                    "Executing: does_not_exist arg 'arg with spaces'"]
+
+
 def test_error(qtbot, proc, caplog, guiprocess_message_mock):
     """Test the process emitting an error."""
     with caplog.atLevel(logging.ERROR, 'message'):