Re: several messages

[Eric Sunshine <sunshine@sunshineco.com>]

On Fri, Sep 2, 2022 at 8:42 AM Johannes Schindelin
<Johannes.Schindelin@gmx.de> wrote:
> On Thu, 1 Sep 2022, Eric Sunshine via GitGitGadget wrote:
> >  t/chainlint.pl                                | 730 ++++++++++++++++++
> >  t/chainlint.sed                               | 399 ----------
> >  t/chainlint/blank-line-before-esac.expect     |  18 +
> >  t/chainlint/blank-line-before-esac.test       |  19 +
> >  ...
>
> This looks like it was a lot of work. And that it would be a lot of work
> to review, too, and certainly even more work to maintain.
>
> Are we really sure that we want to burden the Git project with this much
> stuff that is not actually related to Git's core functionality?
>
> It would be one thing if we could use a well-maintained third-party tool
> to do this job. But adding this to our plate? I hope we can avoid that.

I understand your concerns about review and maintenance burden, and
you're not the first to make such observations; when chainlint.sed was
submitted, it was greeted with similar concerns[1,2], all very
understandable. The key takeaway[3] from that conversation, though,
was that, unlike user-facing features which must be reviewed in detail
and maintained in perpetuity, this is a mere developer aid which can
be easily ejected from the project if it ever becomes a maintenance
burden or shows itself to be unreliable. Potential maintenance burden
aside, a very real benefit of such a tool is that it should help
prevent bugs from slipping into the project going forward[4], which is
indeed the aim of all our developer-focused aids.

In more practical terms, despite initial concerns, in the 4+ years
since its introduction, the maintenance cost of chainlint.sed has been
nearly zero. Very early on, there was a report[5] that chainlint.sed
was showing a false-positive in a `contrib` test script; the developer
quickly responded with a fix[6]. The only other maintenance issues
were a couple dead-simple changes[7,8] to shorten "labels" to support
older versions of `sed`. (As for the chainlint self-tests, the
maintenance cost has been exactly zero). My hope is that chainlint.pl
should have a similar track-record, but it can easily be dropped from
the project if not.

[1]: https://lore.kernel.org/git/xmqqk1q11mkj.fsf@gitster-ct.c.googlers.com/
[2]: https://lore.kernel.org/git/20180712165608.GA10515@sigill.intra.peff.net/
[3]: https://lore.kernel.org/git/CAPig+cRmAkiYqFXwRAkQALDoOo-79r2iAumdEJEZhBnETvL-fw@mail.gmail.com/
[4]: https://lore.kernel.org/git/xmqqin5kw7q3.fsf@gitster-ct.c.googlers.com/
[5]: https://lore.kernel.org/git/20180730181356.GA156463@aiede.svl.corp.google.com/
[6]: https://lore.kernel.org/git/20180807082135.60913-1-sunshine@sunshineco.com/
[7]: https://lore.kernel.org/git/20180824152016.20286-5-avarab@gmail.com/
[8]: https://lore.kernel.org/git/d15ed626de65c51ef2ba31020eeb2111fb8e091f.1596675905.git.gitgitgadget@gmail.com/