Subject: Re: [PATCH v5 7/9] BreakingChanges: announce Rust becoming mandatory

From: Junio C Hamano <[email-masked]>
Date: Tue, 23 Sep 2025 07:17:15 -0700

Patrick Steinhardt <[email-masked]> writes:

> We have made other breaking changes conditional on the wider ecosystem.
> For example, using reftable by default is conditioned on the ecosystem
> having catched up and supporting this new format.
>
> Do we maybe want to do the same with Rust? We can for example add
> something like the following paragraph:
>
>     We will carefully evaluate the impact on downstream distributions
>     before making Rust mandatory in Git 3.0. If we see that the impact
>     on downstream distributions would be significant, we may decide to
>     defer this breaking change. This will also take into account our own
>     learnings with how painful it is to keep Rust an optional component.
>
> The intent would be to alert distributors, but not "blindly" pull the
> trigger. Instead, we should take a step back and evaluate both how the
> Rust ecosystem looks like at the Git 3.0 boundary and how painful it is
> for us to keep it as an optional component.

I have always been assuming that we are prepared to change course if
that is necessary and though that something like that goes without
saying, but if you want to add it to the document, I am perfectly
fine.  It should apply not just Rust but all other entries we list.

Thanks.