[2447] dump a log message if connecting to cc-channel fails.

and suggest checking output from msgq using -v.

src/bin/bind10/bind10_messages.mes

@@ -82,6 +82,21 @@ the boss process will try to force them).
 A debug message. The configurator is about to perform one task of the plan it
 is currently executing on the named component.
 
+% BIND10_CONNECTING_TO_CC_FAIL failed to connect to configuration/command channel; try -v to see output from msgq
+The boss process tried to connect to the communication channel for
+commands and configuration updates during initialization, but it
+failed.  This is a fatal startup error, and process will soon
+terminate after some cleanup.  There can be several reasons for the
+failure, but the most likely cause is that the msgq daemon failed to
+start, and the most likely cause of the msgq failure is that it
+doesn't have a permission to create a socket file for the
+communication.  To confirm that, you can see debug messages from msgq
+by starting BIND 10 with the -v command line option.  If it indicates
+permission problem for msgq, make sure the directory where the socket
+file is to be created is writable for the msgq process.  Note that if
+you specify the -u option to change process users, the directory must
+be writable for that user.
+
 % BIND10_INVALID_STATISTICS_DATA invalid specification of statistics data specified
 An error was encountered when the boss module specified
 statistics data which is invalid for the boss specification file.

src/bin/bind10/bind10_src.py.in

@@ -423,6 +423,7 @@ class BoB:
         while self.cc_session is None:
             # if we have been trying for "a while" give up
             if (time.time() - cc_connect_start) > 5:
+                logger.error(BIND10_STARTING_CC_FAIL)
                 raise CChannelConnectError("Unable to connect to c-channel after 5 seconds")
 
             # try to connect, and if we can't wait a short while