You caught us doing some quick maintenance, temporarily restricting your repository to read-only access.
Issue #362 new
When MacHG idles in the background for some time, it tends to hang fairly reproducibly after a short amount of time (5-10 minutes I'd say).
Not sure what the cause is, so I'm adding this bug report to track it.
os: 10.12.5 (16F73) machg: 1.0.2