LGTM, but I'm not sure if this is related to the error we see on master.

Also, I suppose the pull request branches don't actually get deployed:

if [[ "${CIRCLE_BRANCH}" =~ ^master$|^[0-9]+\.[0-9]+\.X$ ]]; then

We kinda need to test it on master.

Also, I suppose the pull request branches don't actually get deployed

Yes, we cannot deploy PR

Hmm, @adrinjalali what did you do? Seems that you add a new deploy key?
https://github.com/scikit-learn/scikit-learn/settings/keys

I suppose the exact thing which happened in #11550 may have happened here. I only wanted to have sklearn in my dashboard in circle-ci and watch the jobs. I have no idea why that key was added, and have no idea why that affects the github.io repo at all. I removed that key, and see if it works now.

Yep, it was the same issue. Removing the recent read-only deploy key from the sklearn repo had it fixed. It is really counterintuitive!

Yep, it was the same issue. Removing the recent read-only deploy key from the sklearn repo had it fixed. It is really counterintuitive!

Thanks @adrinjalali :)