Displaying preserved build data for GIVENBACK/BUILDERFAIL

[Michael Nelson]

Just creating a bug for something that was noted long ago, but has come up while fixing bug 499095:

From lib/lp/buildmaster/buildergroup.py in BuilderGroup.buildStatus_GIVENBACK:

        # XXX cprov 2006-05-30: Currently this information is not
        # properly presented in the Web UI. We will discuss it in
        # the next Paris Summit, infinity has some ideas about how
        # to use this content. For now we just ensure it's stored.

Screenshot attached. Basically, because we want to preserve the previous build information after a GIVENBACK, while at the same time re-schedule the build for building, the info is very confusing for a limited time until the subsequent build is finished (both the historical builder/start/finish times are presented along with the current).