Re: [PATCH] Add config variable besides env variable to squelch "do-not-use" warning.

From: Elijah Newren <newren@gmail.com>
Date: Jun 16, 2021, 08:03 UTC
Message-ID: <CABPp-BFiD5eYNXsRk=f-5k4oDeCHBW7_pd8iqYYBKsrd6evC9g@mail.gmail.com>
In-Reply-To: <xmqqy2baqvxv.fsf@gitster.g>

On Tue, Jun 15, 2021 at 9:23 PM Junio C Hamano <gitster@pobox.com> wrote:

Show 25 quoted lines

>
> "Daniel Höpfl via GitGitGadget"  <gitgitgadget@gmail.com> writes:
>
> > From: =?UTF-8?q?Daniel=20H=C3=B6pfl?= <daniel@hoepfl.de>
> >
> > In addition to the environment variable FILTER_BRANCH_SQUELCH_WARNING,
> > the git config filter-branch.squelchWarning is checked to see if the
> > usage warning should be squelched.
>
> Thanks for trying to improve the system.
>
> A configuration variable that is used to squelch warning messages
> related to migration and transition typically lives under advice.*
> hierarchy, so something ike "advice.weanOffOfFilterBranch" may be a
> more appropriate name for this new knob.
>
> Having said that.
>
> As this message with environment as an escape hatch was added as a
> way to strongly discourage users from keep using the command, I am
> fairly negative to a change that adds yet another way to make it
> easier to keep using it.
>
> Elijah, who did 9df53c5d (Recommend git-filter-repo instead of
> git-filter-branch, 2019-09-04), added to CC list for input.

Yeah, I generally would like to discourage it but...

Back when we put this strong discouragement and escape hatch in, I wasn't aware of anything that could be done in filter-branch that was hard to do in filter-repo. However, since then, a user reported they wanted to re-sign commits after a rewrite. Since fast-import does not (currently) provide a way to sign commits, and filter-repo is built on top of fast-export and fast-import, this makes it rather difficult for filter-repo to do. (I think it still can, given all the shenanigans I did to create filter-branch-ish as a rewrite of filter-branch on top of filter-repo, but that comes with nearly all the same caveats as filter-branch if used directly, and is a huge amount of code to lift to try to use outside of filter-branch-ish.)

Since there's a valid use for filter-branch (even if rare) that isn't readily done in filter-repo, adding the option Daniel requests makes sense.