> Sure, and I said relatively unchanged compared to bzr. Looking up in bzr, the ondisk format changed several times in incompatible ways. But bzr always had th

> Sure, and I said relatively unchanged compared to bzr. Looking up in bzr, the ondisk format changed several times in incompatible ways. But bzr always had the ability to read and write repositories written using older formats. Each on-disk repository format is implemented as a set of separate Python classes, all exposing the same interface. Git thought it could do without a "repository format version identifier" and a strategy for multiple on-disk formats until version 2.7 (2015). Bzr had everything well planned out since the beginning.