Only the first run of each cron job seems to correctly query gitiles, and subsequent runs run accross errors like:

11:22:00.419
Could not get gitiles log from revision 925d8cd983ceb0b5a0498e2504c08ee181523e9f :: {"error":"Get https://chromium.googlesource.com/a/chromium/src/+log/925d8cd983ceb0b5a0498e2504c08ee181523e9f..master?format=JSON&n=10000: Call error 3: invalid security ticket: 5cd70c7dea7cd943"}