what happened to David Caldwell, the man behind “Emacs For Mac OS X”?

• https://emacsformacosx.com/about
• https://porkrind.org

Since 2019-05-28 his build machine has not created any more builds. I am worried.

Starting 2019-09-01 there have been new entries on the resp. feeds again. Trying to contact him through https://porkrind.org/missives/.