bitbake: command: add error to return of runCommand

Currently, command.py can return an error message from runCommand, due to
being unable to run the command, yet few of our UIs (just hob) can handle it
today. This can result in seeing a TypeError with traceback in certain rare
circumstances.

To resolve this, we need a clean way to get errors back from runCommand,
without having to isinstance() the return value. This implements such a thing
by making runCommand also return an error (or None if no error occurred).

As runCommand now has a method of returning errors, we can also alter the
getCmdLineAction bits such that the returned value is just the action, not an
additional message. If a sync command wants to return an error, it raises
CommandError(message), and the message will be passed to the caller
appropriately.

Example Usage:

    result, error = server.runCommand(...)
    if error:
        log.error('Unable to run command: %s' % error)
        return 1

(Bitbake rev: 717831b8315cb3904d9b590e633000bc897e8fb6)

Signed-off-by: Christopher Larson <chris_larson@mentor.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/ui/knotty.py

@@ -107,9 +107,18 @@ 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
 
     helper = uihelper.BBUIHelper()
 
@@ -125,19 +134,22 @@ 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
@@ -318,14 +330,19 @@ 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