Let me clarify the LTS release and rolling release.The 4.x.x release series is the LTS, and they are all based on 4.0.0 and should be backwards compatible with 4.0.0. The rolling release version will be named as 5.0.0-pre.<date> and be cut from HEAD (so not backwards compatible with 4.0.0), and when we cut the Bazel 5 LTS, the rolling release will start from 6.0.0-pre.<date>.