diff --git a/bitbake/lib/bb/command.py b/bitbake/lib/bb/command.py
index 27b5171a6e..3f28bca257 100644
--- a/bitbake/lib/bb/command.py
+++ b/bitbake/lib/bb/command.py
@@ -44,6 +44,9 @@ class CommandFailed(CommandExit):
         self.error = message
         CommandExit.__init__(self, 1)
 
+class CommandError(Exception):
+    pass
+
 class Command:
     """
     A queue of asynchronous commands for bitbake
@@ -57,21 +60,25 @@ class Command:
         self.currentAsyncCommand = None
 
     def runCommand(self, commandline):
-        try:
-            command = commandline.pop(0)
-            if command in CommandsSync.__dict__:
-                # Can run synchronous commands straight away
-                return getattr(CommandsSync, command)(self.cmds_sync, self, commandline)
-            if self.currentAsyncCommand is not None:
-                return "Busy (%s in progress)" % self.currentAsyncCommand[0]
-            if command not in CommandsAsync.__dict__:
-                return "No such command"
-            self.currentAsyncCommand = (command, commandline)
-            self.cooker.server_registration_cb(self.cooker.runCommands, self.cooker)
-            return True
-        except:
-            import traceback
-            return traceback.format_exc()
+        command = commandline.pop(0)
+        if hasattr(CommandsSync, command):
+            # Can run synchronous commands straight away
+            command_method = getattr(self.cmds_sync, command)
+            try:
+                result = command_method(self, commandline)
+            except CommandError as exc:
+                return None, exc.args[0]
+            except Exception:
+                return None, traceback.format_exc()
+            else:
+                return result, None
+        if self.currentAsyncCommand is not None:
+            return None, "Busy (%s in progress)" % self.currentAsyncCommand[0]
+        if command not in CommandsAsync.__dict__:
+            return None, "No such command"
+        self.currentAsyncCommand = (command, commandline)
+        self.cooker.server_registration_cb(self.cooker.runCommands, self.cooker)
+        return True, None
 
     def runAsyncCommand(self):
         try:
@@ -139,7 +146,11 @@ class CommandsSync:
         """
         Get any command parsed from the commandline
         """
-        return command.cooker.commandlineAction
+        cmd_action = command.cooker.commandlineAction
+        if cmd_action['msg']:
+            raise CommandError(msg)
+        else:
+            return cmd_action['action']
 
     def getVariable(self, command, params):
         """
diff --git a/bitbake/lib/bb/server/process.py b/bitbake/lib/bb/server/process.py
index 4eefe01852..f1e8450b12 100644
--- a/bitbake/lib/bb/server/process.py
+++ b/bitbake/lib/bb/server/process.py
@@ -48,7 +48,7 @@ class ServerCommunicator():
                 if self.connection.poll(.5):
                     return self.connection.recv()
                 else:
-                    return None
+                    return None, "Timeout while attempting to communicate with bitbake server"
             except KeyboardInterrupt:
                 pass
 
diff --git a/bitbake/lib/bb/ui/crumbs/hobeventhandler.py b/bitbake/lib/bb/ui/crumbs/hobeventhandler.py
index 350b00b9ae..5026bf740f 100644
--- a/bitbake/lib/bb/ui/crumbs/hobeventhandler.py
+++ b/bitbake/lib/bb/ui/crumbs/hobeventhandler.py
@@ -108,13 +108,9 @@ class HobHandler(gobject.GObject):
 
     def runCommand(self, commandline):
         try:
-            result = self.server.runCommand(commandline)
-            result_str = str(result)
-            if (result_str.startswith("Busy (") or
-                    result_str == "No such command"):
-                raise Exception('%s has failed with output "%s". ' %
-                        (str(commandline), result_str) +
-                        "We recommend that you restart Hob.")
+            result, error = self.server.runCommand(commandline)
+            if error:
+                raise Exception("Error running command '%s': %s" % (commandline, error))
             return result
         except Exception as e:
             self.commands_async = []
diff --git a/bitbake/lib/bb/ui/depexp.py b/bitbake/lib/bb/ui/depexp.py
index 1a716a88bf..85910f6925 100644
--- a/bitbake/lib/bb/ui/depexp.py
+++ b/bitbake/lib/bb/ui/depexp.py
@@ -198,17 +198,23 @@ class gtkthread(threading.Thread):
 
 def main(server, eventHandler):
     try:
-        cmdline = server.runCommand(["getCmdLineAction"])
-        if cmdline and not cmdline['action']:
-            print(cmdline['msg'])
-            return
-        elif not cmdline or (cmdline['action'] and cmdline['action'][0] != "generateDotGraph"):
+        cmdline, error = server.runCommand(["getCmdLineAction"])
+        if error:
+            print("Error getting bitbake commandline: %s" % error)
+            return 1
+        elif not cmdline:
+            print("Nothing to do.  Use 'bitbake world' to build everything, or run 'bitbake --help' for usage information.")
+            return 1
+        elif not cmdline or cmdline[0] != "generateDotGraph":
             print("This UI is only compatible with the -g option")
-            return
-        ret = server.runCommand(["generateDepTreeEvent", cmdline['action'][1], cmdline['action'][2]])
-        if ret != True:
-            print("Couldn't run command! %s" % ret)
-            return
+            return 1
+        ret, error = server.runCommand(["generateDepTreeEvent", cmdline[1], cmdline[2]])
+        if error:
+            print("Error running command '%s': %s" % (cmdline, error))
+            return 1
+        elif ret != True:
+            print("Error running command '%s': returned %s" % (cmdline, ret))
+            return 1
     except xmlrpclib.Fault as x:
         print("XMLRPC Fault getting commandline:\n %s" % x)
         return
@@ -234,7 +240,9 @@ def main(server, eventHandler):
         try:
             event = eventHandler.waitEvent(0.25)
             if gtkthread.quit.isSet():
-                server.runCommand(["stateStop"])
+                _, error = server.runCommand(["stateStop"])
+                if error:
+                    print('Unable to cleanly stop: %s' % error)
                 break
 
             if event is None:
@@ -310,9 +318,13 @@ def main(server, eventHandler):
                 break
             if shutdown == 1:
                 print("\nSecond Keyboard Interrupt, stopping...\n")
-                server.runCommand(["stateStop"])
+                _, error = server.runCommand(["stateStop"])
+                if error:
+                    print('Unable to cleanly stop: %s' % error)
             if shutdown == 0:
                 print("\nKeyboard Interrupt, closing down...\n")
-                server.runCommand(["stateShutdown"])
+                _, error = server.runCommand(["stateShutdown"])
+                if error:
+                    print('Unable to cleanly shutdown: %s' % error)
             shutdown = shutdown + 1
             pass
diff --git a/bitbake/lib/bb/ui/goggle.py b/bitbake/lib/bb/ui/goggle.py
index b2fd2741aa..c0785b7990 100644
--- a/bitbake/lib/bb/ui/goggle.py
+++ b/bitbake/lib/bb/ui/goggle.py
@@ -80,16 +80,19 @@ def main (server, eventHandler):
     running_build.connect ("build-failed", running_build_failed_cb)
 
     try:
-        cmdline = server.runCommand(["getCmdLineAction"])
-        if not cmdline:
+        cmdline, error = server.runCommand(["getCmdLineAction"])
+        if err:
+            print("Error getting bitbake commandline: %s" % error)
+            return 1
+        elif not cmdline:
             print("Nothing to do.  Use 'bitbake world' to build everything, or run 'bitbake --help' for usage information.")
             return 1
-        elif not cmdline['action']:
-            print(cmdline['msg'])
+        ret, error = server.runCommand(cmdline)
+        if error:
+            print("Error running command '%s': %s" % (cmdline, error))
             return 1
-        ret = server.runCommand(cmdline['action'])
-        if ret != True:
-            print("Couldn't get default commandline! %s" % ret)
+        elif ret != True:
+            print("Error running command '%s': returned %s" % (cmdline, ret))
             return 1
     except xmlrpclib.Fault as x:
         print("XMLRPC Fault getting commandline:\n %s" % x)
diff --git a/bitbake/lib/bb/ui/knotty.py b/bitbake/lib/bb/ui/knotty.py
index 6ac3d85b1e..b99a121729 100644
--- a/bitbake/lib/bb/ui/knotty.py
+++ b/bitbake/lib/bb/ui/knotty.py
@@ -217,9 +217,19 @@ class TerminalFilter(object):
 def main(server, eventHandler, tf = TerminalFilter):
 
     # Get values of variables which control our output
-    includelogs = server.runCommand(["getVariable", "BBINCLUDELOGS"])
-    loglines = server.runCommand(["getVariable", "BBINCLUDELOGS_LINES"])
-    consolelogfile = server.runCommand(["getVariable", "BB_CONSOLELOG"])
+    includelogs, error = server.runCommand(["getVariable", "BBINCLUDELOGS"])
+    if error:
+        logger.error("Unable to get the value of BBINCLUDELOGS variable: %s" % error)
+        return 1
+    loglines, error = server.runCommand(["getVariable", "BBINCLUDELOGS_LINES"])
+    if error:
+        logger.error("Unable to get the value of BBINCLUDELOGS_LINES variable: %s" % error)
+        return 1
+    consolelogfile, error = server.runCommand(["getVariable", "BB_CONSOLELOG"])
+    if error:
+        logger.error("Unable to get the value of BB_CONSOLELOG variable: %s" % error)
+        return 1
+
     if sys.stdin.isatty() and sys.stdout.isatty():
         log_exec_tty = True
     else:
@@ -240,19 +250,22 @@ def main(server, eventHandler, tf = TerminalFilter):
         logger.addHandler(consolelog)
 
     try:
-        cmdline = server.runCommand(["getCmdLineAction"])
-        if not cmdline:
+        cmdline, error = server.runCommand(["getCmdLineAction"])
+        if error:
+            logger.error("Unable to get bitbake commandline arguments: %s" % error)
+            return 1
+        elif not cmdline:
             print("Nothing to do.  Use 'bitbake world' to build everything, or run 'bitbake --help' for usage information.")
             return 1
-        elif not cmdline['action']:
-            print(cmdline['msg'])
+        ret, error = server.runCommand(cmdline)
+        if error:
+            logger.error("Command '%s' failed: %s" % (cmdline, error))
             return 1
-        ret = server.runCommand(cmdline['action'])
-        if ret != True:
-            print("Couldn't get default commandline! %s" % ret)
+        elif ret != True:
+            logger.error("Command '%s' failed: returned %s" % (cmdline, ret))
             return 1
     except xmlrpclib.Fault as x:
-        print("XMLRPC Fault getting commandline:\n %s" % x)
+        logger.error("XMLRPC Fault getting commandline:\n %s" % x)
         return 1
 
     parseprogress = None
@@ -447,14 +460,19 @@ def main(server, eventHandler, tf = TerminalFilter):
             if ioerror.args[0] == 4:
                 pass
         except KeyboardInterrupt:
+            import time
             termfilter.clearFooter()
             if main.shutdown == 1:
                 print("\nSecond Keyboard Interrupt, stopping...\n")
-                server.runCommand(["stateStop"])
+                _, error = server.runCommand(["stateStop"])
+                if error:
+                    logger.error("Unable to cleanly stop: %s" % error)
             if main.shutdown == 0:
-                interrupted = True
                 print("\nKeyboard Interrupt, closing down...\n")
-                server.runCommand(["stateShutdown"])
+                interrupted = True
+                _, error = server.runCommand(["stateShutdown"])
+                if error:
+                    logger.error("Unable to cleanly shutdown: %s" % error)
             main.shutdown = main.shutdown + 1
             pass
 
diff --git a/bitbake/lib/bb/ui/ncurses.py b/bitbake/lib/bb/ui/ncurses.py
index f6ea7f9bca..98647fc3e0 100644
--- a/bitbake/lib/bb/ui/ncurses.py
+++ b/bitbake/lib/bb/ui/ncurses.py
@@ -236,15 +236,18 @@ class NCursesUI:
         shutdown = 0
 
         try:
-            cmdline = server.runCommand(["getCmdLineAction"])
+            cmdline, error = server.runCommand(["getCmdLineAction"])
             if not cmdline:
                 print("Nothing to do.  Use 'bitbake world' to build everything, or run 'bitbake --help' for usage information.")
                 return
-            elif not cmdline['action']:
-                print(cmdline['msg'])
+            elif error:
+                print("Error getting bitbake commandline: %s" % error)
                 return
-            ret = server.runCommand(cmdline['action'])
-            if ret != True:
+            ret, error = server.runCommand(cmdline)
+            if error:
+                print("Error running command '%s': %s" % (cmdline, error))
+                return
+            elif ret != True:
                 print("Couldn't get default commandlind! %s" % ret)
                 return
         except xmlrpclib.Fault as x:
@@ -345,10 +348,14 @@ class NCursesUI:
                     exitflag = True
                 if shutdown == 1:
                     mw.appendText("Second Keyboard Interrupt, stopping...\n")
-                    server.runCommand(["stateStop"])
+                    _, error = server.runCommand(["stateStop"])
+                    if error:
+                        print("Unable to cleanly stop: %s" % error)
                 if shutdown == 0:
                     mw.appendText("Keyboard Interrupt, closing down...\n")
-                    server.runCommand(["stateShutdown"])
+                    _, error = server.runCommand(["stateShutdown"])
+                    if error:
+                        print("Unable to cleanly shutdown: %s" % error)
                 shutdown = shutdown + 1
                 pass