Comment 10 for bug 1837673

Ok, this ppa is ready for testing:

https://launchpad.net/~ahasenack/+archive/ubuntu/october-certbot-sru/

Or:

sudo add-apt-repository ppa:ahasenack/october-certbot-sru

I was able to verify today that the existing xenial client indeed stopped working (we are in the first brown-out day):
Starting new HTTPS connection (1): acme-v01.api.letsencrypt.org
An unexpected error occurred:
The client lacks sufficient authorization :: Account creation on ACMEv1 is disabled. Please upgrade your ACME client to a version that supports ACMEv2 / RFC 8555. See https://community.letsencrypt.org/t/end-of-life-plan-for-acmev1/88430 for details.
Please see the logfiles in /var/log/letsencrypt for more details.

I then upgraded to the packages from the ppa, re-ran "certbot run", and then it used the acmev2 endpoint and worked.

For the actual sru verification I'll just have the verifier check the url that is used, as the v1 endpoint will probably be active by then again (unless this update misses the deadline).