remove signal sent after debug shell exits

subiquity/core.py

@@ -17,8 +17,6 @@ import logging
 import os
 import platform
 
-import urwid
-
 from subiquitycore.core import Application
 
 from subiquity.models.subiquity import SubiquityModel
@@ -46,8 +44,6 @@ installed system will be mounted at /target.""")
 
 class Subiquity(Application):
 
-    signals = ['debug-shell-exited']
-
     snapd_socket_path = '/run/snapd.socket'
 
     from subiquity.palette import COLORS, STYLES, STYLES_MONO
@@ -127,8 +123,5 @@ class Subiquity(Application):
             os.system("clear")
             print(DEBUG_SHELL_INTRO)
 
-        def _after():
-            urwid.emit_signal(self, 'debug-shell-exited')
-
         self.run_command_in_foreground(
-            "bash", before_hook=_before, after_hook=_after, cwd='/')
+            "bash", before_hook=_before, cwd='/')

subiquitycore/core.py

@@ -268,7 +268,7 @@ class DummyKeycodesFilter:
         return keys
 
 
-class Application(metaclass=urwid.MetaSignals):
+class Application:
 
     # A concrete subclass must set project and controllers attributes, e.g.:
     #