Starting with version 2.40 of the Email Extension Plugin, it uses 'getCommitId' on the ChangeLogSet.Entry object to get the commit id. However, the Mercurial Plugin only provides this information through the MercurialChangeset.getRevision method, which the Email Extension Plugin used to access through reflection.

This is breaking e-mail configurations that used to work with Email Extension Plugin version 2.34. Specifically, the problem is that the %r (revision) formatting option for the ${CHANGES} option no longer works and will always show as 'null'.

I suspect that the %d (date) option might be broken for a similar reason, though I have not tested that: In this commit: https://github.com/jenkinsci/email-ext-plugin/commit/6453a56cdcc82d2d7f085e8dba9c2b7032cb112a the Email Extension Plugin seems to have been modified to use getTimeStamp instead of getDate, which is also not yet implemented by the MercurialChangeSet.

I've put the priority on 'major' because the only workaround is to use an older version of the Email Extension Plugin, which is undesirable because a different functionality of older versions of the Email Extension Plugin is not working under Jenkins 1.591 (the ability to put information about failed unit tests in the e-mail).