- When "git config protocol.version 2" is used, there is no warning/message when the remote returns a response in v0 format. This leads to any issues related to slow(er) git caused by old protocol use being unnoticed, leading to wasted time debugging. - v2 protocol has been standard since 2.26 https://github.com/git/git/blob/master/Documentation/RelNotes/2.26.0.txt#L101 However, there are still large providers (that rhyme with Nuntucket...) that do not support it/have actively disabled it now (years after the release) Additionally, we encountered various self-hosted git servers that had the protocol version restricted to 1 in their initial setup and this being forgotten about. This led to unnecessarily slow fetches by their users unaware of this problem, since git just silently accepts v1 (0) protocol. Since v2 is the default protocol, I think it would be expected that if a non-default protocol reply is returned, there is a message shown to the user (like e.g. the detached head warning) to make the user aware that an outdated git protocol was used making git slow. Otherwise, this (currently) leads to reports that e.g. git fetch is getting slower and slower (as repo sizes increase over time). However the issue in all cases we have handled so far, has always been that the old protocol was used without the user being aware of it and not an issue with git itself. e.g. If protocol.version is not explicitly set or v2 and both the local and server git version are >=2.26 and the reply is not in v2 protocol format
