A week and a half ago, the Platform Engineering Director for Wikimedia clarified how he would like to see volunteers helping with MediaWiki tarball releases.
Instead of doing some other work I had planned for this weekend (Yay, procrastination!), I managed to put together a 1.20 RC tarball and announce it.
If you get a chance to test this, let me know. If you find a bug, file it in bugzilla. Hopefully we’ll have something ready for release in a couple of weeks.