Maybe a system groovy scripts would be a good direction (groovy script plugin). Just add a new script as your build step. You can access your AbstractBuild object by running the following code:
import hudson.model.*
import hudson.util.*
import hudson.scm.*
def thr = Thread.currentThread()
def build = thr?.executable
I'm trying to solve a similar problem currently, but my use case change a bit. I try to copy the changes from Upstream project in the similar way that BlameSubversion plugin does. Unfortunately I can't use the mentioned above SCM plugin because it doesn't work with post-commit-hook, so I have to write my own solution.
Take a look at copyChangeLogFromTriggerJob and copyRevisionFromTriggerJob methods to get know how BlameSubversion does that.
I'm able to copy changes and revision but I'm still fighting with ChangeLogParser.
I would be gladfull for any help as well.