Fixing the Jenkins scm-sync-configuration plugin

I've often found that anytime you upgrade Jenkins versions, the plug-ins that accompany it often break.  The other day, the scm-sync-configuration plugin that helps manage and store the XML-based configuration files stopped working after upgrading to Ubuntu 14.04 and the Jenkins package included with it.  The plugin appeared to copy files to the scm-sync-configuration/ directory but never seemed to commit the changes to the Git repo.  What was wrong?

It turns out that the issue was already reported since April 2014.  The workaround for most people was to downgrade from Git 1.9, which comes with the Ubuntu 14.04 installs, to Git 1.8 versions.   It so happens that the maven-scm-provider-git plugin on which this Jenkins plugin depends attempts to parse the output of the "git status".  When the formatting change, it broke the ability to ascertain what changes had been made.  The related ticket is here:

https://jira.codehaus.org/browse/SCM-738

The issue for this Maven project was fixed subsequently, but the dependent packages that the scm-sync-configuration plugin had to be updated.  Furthermore, you had to check that the maven-scm-api that has this fix actually got updated to 1.9.1, since missing one upgrade dependency meant that it would stay at an older version.

The changes for this fix are here:

https://github.com/jenkinsci/scm-sync-configuration-plugin/pull/21

The other issue, which was much less obvious, was that there's a related XML file that determines what source code control systems are supported.  For some reason, only Subversion (SVN) was declared, which broke tests for the Git-related ones.   It wasn't so obvious until several hours of tracing through the source code and noticing that the ScmManager class only had one ScmProvider declared.  Apparently this plugin uses a package called Plexus to load this information, which relies on XML configurations such as this file.