Hello,
I have added Jenkins jobs to run your extension PHPUnit tests with hhvm. Since the tests might be failing, the job is not triggered on patchset proposal, one has to comment in Gerrit 'check experimental'.
Please do so on your favourite extensions or patches and report back any issue there :]
I will make the job to trigger on patch proposal by the end of the week.
Note: I have already added an HHVM based job for mediawiki-core. It is non voting for now pending upgrade of our hhvm version.
cheers,