bitbake: fetch2: fix malformed URL causing a useless traceback

The implementation of NoMethodError and MalformedUrl was broken - if you
just set self.args in an exception class to a string it treats it as a
list and then fails later on with a TypeError due to the number of
arguments not matching up.

This nasty exception during exception handling was breaking the normal
exception flow (fixed separately), which meant that if you had a
malformed URL or invalid protocol in SRC_URI you would get the
following:

ERROR: Command execution failed: Traceback (most recent call last):
  File "/home/user/poky/poky/bitbake/lib/bb/command.py", line 84, in runAsyncCommand
    self.cooker.updateCache()
  File "/home/user/poky/poky/bitbake/lib/bb/cooker.py", line 1207, in updateCache
    if not self.parser.parse_next():
  File "/home/user/poky/poky/bitbake/lib/bb/cooker.py", line 1694, in parse_next
    logger.error('Unable to parse %s', value.recipe,
AttributeError: 'exceptions.TypeError' object has no attribute 'recipe'

A specific fix for [YOCTO #2977].

(Bitbake rev: 9d4150d99051d24ff218e8a43664ceaf524b19c7)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/fetch2/__init__.py

@@ -54,7 +54,7 @@ class MalformedUrl(BBFetchException):
          msg = "The URL: '%s' is invalid and cannot be interpreted" % url
          self.url = url
          BBFetchException.__init__(self, msg)
-         self.args = url
+         self.args = (url,)
 
 class FetchError(BBFetchException):
     """General fetcher exception when something happens incorrectly"""
@@ -87,7 +87,7 @@ class NoMethodError(BBFetchException):
          msg = "Could not find a fetcher which supports the URL: '%s'" % url
          self.url = url
          BBFetchException.__init__(self, msg)
-         self.args = url
+         self.args = (url,)
 
 class MissingParameterError(BBFetchException):
     """Exception raised when a fetch method is missing a critical parameter in the url"""