This is a minimal demonstration of a problem that's cropped up, where committing changes via this API method has stopped working: https://developer.github.com/v3/repos/contents/#update-a-file
But only sometimes! It does work on "small" repos, but the same process fails inexplicably when attempted on a "big" repo.
Below I compare results committing against the README.md of two repos:
- https://github.com/whosonfirst/whosonfirst-sources (small)
- https://github.com/whosonfirst-data/whosonfirst-data-venue-us-new-york (big)
First, get a copy of the current README (base64 content + sha hash).