[Buildbot-commits] [Buildbot] #2309: When 'nextBuild' picks something other than the oldest build, build request merging results in incorrect revision number being used for the build

[Buildbot]

#2309: When 'nextBuild' picks something other than the oldest build, build request
merging results in incorrect revision number being used for the build
--------------------+-----------------------
Reporter:  bdash    |      Owner:
    Type:  defect   |     Status:  new
Priority:  major    |  Milestone:  undecided
 Version:  0.8.6p1  |   Keywords:
--------------------+-----------------------
 On the [http://build.webkit.org/ WebKit Buildbot] we recently altered our
 configuration to
 [http://trac.webkit.org/changeset/117508/trunk/Tools/BuildSlaveSupport
 prioritize the newest pending build request] by using a `nextBuild`
 function on the builder configuration. However, we have noticed that this
 causes Buildbot to build the wrong revision if merging of build requests
 is enabled for that builder.
 Such an example of the incorrect building can be seen
 [http://build.webkit.org/builders/Lion%20Release%20%28Build%29/builds/10276
 here].
 In this instance, change number 430 (SVN r119458) was selected by our
 `pickLatestBuild` function due to being the most recent pending build at
 the time. Note however that the source stamp refers to SVN r119457, as do
 the commands that are later invoked. This appears to be due to the manner
 in which the merging of build requests occurs. It seems as though all
 eligible requests are merged in to the request that
 the `nextBuild` function returns. This results in the changes being listed
 out of order on the build page (430, 428, 429 in the example above). Code
 elsewhere in Buildbot appears to look only at the last change in the build
 request when determining the SVN revision to work with. This results in it
 picking the SVN revision from change number 429 (SVN r119457) rather than
 using the most recent SVN revision from the set of changes associated with
 the build.

-- 
Ticket URL: <http://trac.buildbot.net/ticket/2309>
Buildbot <http://buildbot.net/>
Buildbot: build/test automation