bitbake: hob/hobeventhandler: Describe the runCommand failure exception

[YOCTO #1245]

(Bitbake rev: 17f28f09452f70dfb67fce9a397a99deec84dfe5)

Signed-off-by: Constantin Musca <constantinx.musca@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/ui/crumbs/hobeventhandler.py

@@ -105,7 +105,9 @@ class HobHandler(gobject.GObject):
             result_str = str(result)
             if (result_str.startswith("Busy (") or
                     result_str == "No such command"):
-                raise Exception(result_str)
+                raise Exception('%s has failed with output "%s". ' %
+                        (str(commandline), result_str) +
+                        "We recommend that you restart Hob.")
             return result
         except Exception as e:
             self.commands_async = []