Hudson SVN Revisions/Changes Went Out of Sync

A project in our Hudson had been stalled for 3 weeks, for its svn revisions/changes, and I had to do a manual svn update in its workspace directory to make sure the build runs correctly. What exactly happened is that, Hudson was not checking out the HEAD revisions of these modules but the old revisions before it ran into this problem, besides, the "Changes" page showed no information other than those builds that happened 3 weeks ago.

So I thought there could be some state being held by it and I tried:

• To turn off using SVN update but SVN checkout for every build.
• To change the revision values in the svnexternals.txt.
• etc.

None of these helped 'til I changed the synchronousPolling in hudson.triggers.SCMTrigger.xml from false to true and Hudson finally polled the latest revisions and updated the "Changes" page for the newly triggered build. This reset the state and behaviour (of polling all in one go) and therefore resolved my problem.

Just a tip if any of you ever hit into this.

yc