IIRC it goes further than that. Previous stable (0) compiles current source (1) into a temporary new stable (2), then (2) is used to compile (1) into the actua

IIRC it goes further than that. Previous stable (0) compiles current source (1) into a temporary new stable (2), then (2) is used to compile (1) into the actual release version (3). Could be wrong though, it has been a long time since I stumbled over a description of the release process.