Re: [PATCH v2 4/5] Makefile: use the sha1collisiondetection submodule by default

Junio C Hamano [off-list ref] writes:

That endgame allows us not force people to grab an essential part of
the codebase as an external dependency from another place, which
feels quite bad, especially when their primary interest is not in
dogfooding submodule but in building a working version of Git.

Removing one and keeping the other between the two will make the
distribution more streamlined by removing the build-time knob we
need to tweak, but the one that gets removed does not have to be the
in-tree one that allows people to "git clone" from just one place.

Perhaps this may deserve a bit more explanation.

I wouldn't be so against "let's do submodule-only" if this were not
SHA-1 implementation but something like gitk and git-gui.  An optional
part of a system that it is safe to leave to individual builders if
they want to fetch and use that part *is* an ideal target to bind as
a submodule to the system.

It's just the "default SHA-1 implementation" is at the far opposite
end of the spectrum from "an optional part", and our use of
submodule to bind this code is definitely *not* because it makes
sense to use submodule in that context; it is because developers
(not necessarily those who consume Git sourcecode) *wanted* to use
submodule there, regardless of the real merit of doing so.

And that is why I do not feel entirely happy with the step 4/5 and
also I feel moderately strongly against the step 5/5.  These two
steps have a "developer first" smell that disgusts me.