[layer8]

“Meta” would normally mean that a metarepo relates to a repo like a repo relates to a file. That would imply an orthogonal versioning axis, similar to a bitemporal database.

I find the term confusing here because that’s not really what it is (if my understanding is correct).

[vlad_ivanov]

It does, in fact, relate to a repo like a repo relates to a file! Because every projection only contains related history and subtrees – much like if you were looking at a history of a file in a git repository

[layer8]

So I can “commit” a repo containing some history as the new version of a previous repo containing a different history?

[vlad_ivanov]

You can, if histories are related. They usually are - you add commits on top. Your history will be reverse-transformed in such a way so that its impact on the whole metarepo can be assessed. So if you modified a file in a library that ten other applications depend on, those applications would get this modification applied and would trigger a CI run to verify your change.