Make it possible to use pdb for debugging.

doc/HACKING.asciidoc

@@ -151,9 +151,7 @@ Debugging
 ~~~~~~~~~
 
 In the `qutebrowser.utils.debug` module there are some useful functions for
-debugging. In particular you should use `set_trace` from
-`qutebrowser.utils.debug` instead of `pdb` to set breakpoints or you'll get
-annoying Qt error messages.
+debugging.
 
 When starting qutebrowser with the `--debug` flag you also get useful debug
 logs. You can add +--logfilter _category[,category,...]_+ to restrict logging

qutebrowser/qutebrowser.py

@@ -116,7 +116,11 @@ def main():
     # We do this import late as we need to fix harfbuzz first.
     from qutebrowser import app
     from qutebrowser.utils import debug
+    from PyQt5.QtCore import pyqtRemoveInputHook
     import PyQt5.QtWidgets as QtWidgets
+    # We don't use qutebrowser via the interactive shell, but we want to be
+    # able to use pdb.
+    pyqtRemoveInputHook()
     app = app.Application(args)
     # We set qApp explicitely here to reduce the risk of segfaults while
     # quitting.

qutebrowser/utils/debug.py

@@ -20,7 +20,6 @@
 """Utilities used for debugging."""
 
 import re
-import pdb
 import sys
 import types
 import functools
@@ -32,24 +31,6 @@ from qutebrowser.commands import cmdutils
 from qutebrowser.config import config, style
 
 
-@cmdutils.register(debug=True, name='debug-set-trace')
-def set_trace():
-    """Break into the debugger in the shell.
-
-    //
-
-    Based on http://stackoverflow.com/a/1745965/2085149
-    """
-    if sys.stdout is not None:
-        sys.stdout.flush()
-    print()
-    print("When done debugging, remember to execute:")
-    print("  from PyQt5 import QtCore; QtCore.pyqtRestoreInputHook()")
-    print("before executing c(ontinue).")
-    pyqtRemoveInputHook()
-    pdb.set_trace()
-
-
 @cmdutils.register(debug=True)
 def debug_crash(typ='exception'):
     """Crash for debugging purposes.