lp-buildd crashes on recipe failures: too many values to unpack

[Colin Watson]

launchpad-buildd 116 introduced a regression in recipe handling. When buildrecipe exits with 202 to indicate a failure to install build-dependencies, we get:

2013/10/02 20:16 +0000 [-] Iterating with success flag 202 against stage BUILD_RECIPE
2013/10/02 20:16 +0000 [-] Unhandled Error
 Traceback (most recent call last):
   File "/usr/lib/python2.5/site-packages/twisted/internet/process.py", line 639, in childConnectionLost
     self.maybeCallProcessEnded()
   File "/usr/lib/python2.5/site-packages/twisted/internet/process.py", line 652, in maybeCallProcessEnded
     self.reapProcess()
   File "/usr/lib/python2.5/site-packages/twisted/internet/process.py", line 540, in reapProcess
     self.processEnded(status)
   File "/usr/lib/python2.5/site-packages/twisted/internet/process.py", line 628, in processEnded
     self.maybeCallProcessEnded()
 --- <exception caught here> ---
   File "/usr/lib/python2.5/site-packages/twisted/internet/process.py", line 668, in maybeCallProcessEnded
     self.proto.processEnded(failure.Failure(e))
   File "/usr/lib/launchpad-buildd/lpbuildd/slave.py", line 86, in processEnded
     self.notify(statusobject.value.exitCode)
   File "/usr/lib/launchpad-buildd/lpbuildd/debian.py", line 123, in iterate
     func(success)
   File "/usr/lib/launchpad-buildd/lpbuildd/sourcepackagerecipe.py", line 105, in iterate_BUILD_RECIPE
     _, mo = self.searchLogContents([rx, re.M])
   File "/usr/lib/launchpad-buildd/lpbuildd/debian.py", line 193, in searchLogContents
     for pattern, flags in patterns_and_flags]
 exceptions.ValueError: too many values to unpack