That seems like a good idea to prevent regressions if anyone knows how to do that.

For python.org/dev/'s buildbot fleet, the configuration of what configure and make flags happens via https://github.com/python/buildmaster-config/tree/master/master/custom - note the 'def setup' overriding that needs to be done in factories.py so that older branches {'3.7', '3.8', '3.9'} are not configured using the flag.

Coordinate with the owner of a particular buildbot to make sure the system has the requisite installed libraries and headers.

I manually tested a Linux build against libedit, it builds and works.  But test_readline has failures.  tracking those in https://bugs.python.org/issue43172