Re: Suppressing filter-branch warning

From: Junio C Hamano <gitster@pobox.com>
Date: Nov 6, 2020, 18:06 UTC
Message-ID: <xmqqo8kafjgt.fsf@gitster.c.googlers.com>
In-Reply-To: <20201106090443.GA20407@black.spass-am-geraet.de>

Daniel Höpfl <daniel@hoepfl.de> writes:

Show 27 quoted lines

> Hello there,
>
> What did you do before the bug happened? (Steps to reproduce your issue)
> git filter-branch -f --env-filter '' --tag-name-filter cat -- HEAD
>
> What did you expect to happen? (Expected behavior)
> See below (difference).
>
> What happened instead? (Actual behavior)
> When using git filter-branch, the following message is shown:
>
> ----------8<-----------------------------------------------------
> WARNING: git-filter-branch has a glut of gotchas generating mangled history
>         rewrites.  Hit Ctrl-C before proceeding to abort, then use an
>         alternative filtering tool such as 'git filter-repo'
>         (https://github.com/newren/git-filter-repo/) instead.  See the
>         filter-branch manual page for more details; to squelch this warning,
>         set FILTER_BRANCH_SQUELCH_WARNING=1.
> ----------8<-----------------------------------------------------
>
> You can suppress this by setting the environment variable shown.
>
> What's different between what you expected and what actually happened?
>
> Normally, when git introduces this kind of change, there is a
> git config variable that one can set to suppress it.
> That way one has fine grade control when to suppress it (one repo only...globally).

I think this comes from 9df53c5d (Recommend git-filter-repo instead of git-filter-branch, 2019-09-04).

FWIW, I personally do not think an environment is a worse choice over configuration variable in this particular case. The large scale rewriting of the entire history in the repository by its nature is an one-off operation that ought to happen only rarely, so a one-shot

	$ FILTER_BRANCH_SQUELCH_WARNING=1 git filter-branch ...

that reminds the user every time would be more appropriate than a configuration variable that has a more permanent squelching effect.

If it were a new command line option may have been even better, as an environment variable can be defined in .*rc and forgotten, but a command line option needs to be typed every time and would serve as a better reminder (yes, I know it can also be aliased away, so it may not make much practical difference either way).

But I'll let the author of the feature to comment.

Thanks.