bzr retry logic should re-raise exception after max retries

[Francis Ginther]

The retry logic that was added for 0.36 absorbs the exception and returns a "None" to the caller. This causes bad things to happen because not all of the calling code was designed to handle this. Instead, just re-raise the last exception that was encountered and let it propagate up to the calling code.

From the included log, we see an example of this happening. A merge conflict is found as an exception and it is retried as expected. Unfortunately at the end, the build doesn't error out, it keeps going. Bad things happen later on.

[log]
INFO:pbuilderjenkins:Branch setup taking place using recipes
Building tree.
Retrieving 'bzr+ssh://<email address hidden>/~renatofilho/mediaplayer-app/fix-1233268' to put at 'work'.
Merging 'lp:mediaplayer-app' in to 'work'.
Not attempting to fix packaging branch ancestry, missing pristine tar data for version 0.20.5+13.10.20130930.1.
Text conflict in src/qml/player.qml
1 conflicts encountered.
bzr: ERROR: Conflicts from merge
ERROR:pbuilderjenkins:Exception: Error while preparing from recipe:
Building tree.
Retrieving 'bzr+ssh://<email address hidden>/~renatofilho/mediaplayer-app/fix-1233268' to put at 'work'.
bzr: ERROR: Conflicts... aborting.
ERROR:pbuilderjenkins:Exception: Error while preparing from recipe:
Building tree.
Retrieving 'bzr+ssh://<email address hidden>/~renatofilho/mediaplayer-app/fix-1233268' to put at 'work'.
bzr: ERROR: Conflicts... aborting.
ERROR:pbuilderjenkins:Exception: Error while preparing from recipe:
INFO:pbuilderjenkins:Setting up hooks
INFO:pbuilderjenkins:Adding D09apt_update hook ("apt-get update" call)
DEBUG:pbuilderjenkins:Temporary hooks directory: /tmp/tmpVRInSR
DEBUG:pbuilderjenkins:Creating hook from D09add_ppa~ubuntu-unity~daily-build
DEBUG:pbuilderjenkins:Parsed into ubuntu-unity, daily-build
DEBUG:pbuilderjenkins:Adding hook: A10checklicenseheaders
DEBUG:pbuilderjenkins:Adding hook: D09apt_update
INFO:pbuilderjenkins:Running hooks
INFO:pbuilderjenkins:Chroot build starting...

[Francis Ginther (fginther)]

The fix should be to just re-raise the last exception.

Here's the same operation with the fix:
INFO:pbuilderjenkins:Branch setup taking place using recipes
Building tree.
Retrieving 'lp:~renatofilho/mediaplayer-app/fix-1233268' to put at 'work'.
Merging 'lp:mediaplayer-app' in to 'work'.
Not attempting to fix packaging branch ancestry, missing pristine tar data for version 0.20.5+13.10.20130930.1.
Text conflict in src/qml/player.qml
1 conflicts encountered.
bzr: ERROR: Conflicts from merge
ERROR:pbuilderjenkins:Exception: Error while preparing from recipe:
Building tree.
Retrieving 'lp:~renatofilho/mediaplayer-app/fix-1233268' to put at 'work'.
bzr: ERROR: Conflicts... aborting.
ERROR:pbuilderjenkins:Exception: Error while preparing from recipe:
Building tree.
Retrieving 'lp:~renatofilho/mediaplayer-app/fix-1233268' to put at 'work'.
bzr: ERROR: Conflicts... aborting.
ERROR:pbuilderjenkins:Exception: Error while preparing from recipe:
ERROR:pbuilderjenkins:Error during build execution
ERROR:pbuilderjenkins:Error while preparing from recipe:
pbuilder returned ERROR.
Build step 'Debian PBuilder NG' marked build as failure
There is no public Hudson instance configured for this project
Finished: FAILURE

[PS Jenkins bot (ps-jenkins)]

Fix committed into lp:pbuilderjenkins at revision 123, scheduled for release in pbuilderjenkins, milestone Unknown