Re: [PATCH] Makefile: add and use the ".DELETE_ON_ERROR" flag

From: Felipe Contreras <felipe.contreras@gmail.com>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
	"Felipe Contreras" <felipe.contreras@gmail.com>
Cc: Junio C Hamano <gitster@pobox.com>, Jeff King <peff@peff.net>,
	Taylor Blau <me@ttaylorr.com>,
	git@vger.kernel.org
Subject: Re: [PATCH] Makefile: add and use the ".DELETE_ON_ERROR" flag
Date: Fri, 02 Jul 2021 19:41:36 -0500	[thread overview]
Message-ID: <60dfb240ec471_3dd220879@natae.notmuch> (raw)
In-Reply-To: <87tulecfx7.fsf@evledraar.gmail.com>

Ævar Arnfjörð Bjarmason wrote:
> On Wed, Jun 30 2021, Felipe Contreras wrote:
> > Ævar Arnfjörð Bjarmason wrote:
> 
> >> Even if you don't care about the end result or making git easier to hack
> >> on for people who don't share your setup,
> >
> > I don't know about Junio, I do want to make git easier to hack for
> > people that don't share my setup, but I would like to know what that
> > setup is.
> 
> I think all of this is covered in detail upthread.

From [1] I understand some systems have a problem clobbering a binary
that is being run. So if you are running a test that is using a binary
that you are rebuilding at the same time, you get an error.

OK.

I still don't see why anyone would want to rebuild the binary in the
middle of running tests. The result of the tests is only meaningful for
a particular build. This is what I don't get. I get that you want to do
this, what I don't get is *why*.

In order to be able to rebuild _and_ keep running the tests for a
certain build an out-of-source build is needed. Modern build systems
like CMake and Meson do these kinds of builds by default. In fact, Meson
doesn't support anything else.

With an in-source build such as in git, I first stop the tests, and
then rebuild, and that's what I would expect everyone else to do. I
don't think it has been explained why anybody wouldn't.

Cheers.

[1] https://lore.kernel.org/git/871r8r1hwe.fsf@evledraar.gmail.com/

-- 
Felipe Contreras