Re: [PATCH v2 4/5] Makefile: add the ".DELETE_ON_ERROR" flag

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Mar 31, 2021, 22:29 UTC
Message-ID: <nycvar.QRO.7.76.6.2104010026440.54@tvgsbejvaqbjf.bet>
In-Reply-To: <xmqq35wb891a.fsf@gitster.g>

Hi,

On Wed, 31 Mar 2021, Junio C Hamano wrote:

Show 17 quoted lines

> Jeff King <peff@peff.net> writes:
>
> > I don't know how paranoid we want to be about this, especially the
> > latter. My general inclination is to prefer "commit" systems as more
> > robust, but it is just a Makefile.
>
> ;-)
>
> As an old timer, I've written "gen >$@+ && mv $@+ $@" all the time
> myself, but it is ugly and felt a bit too conservative.  I do not
> think it is wise to overnight remove all the existing "generate in
> temporary, move to the final" patterns and delegate $(MAKE) to take
> care of failed generator with this mechanism, but I actually would
> feel it probably gives us a cleaner Makefile in the longer term.  At
> least "bugs in $(MAKE)" won't be our sole problem (i.e. all other
> projects that rely on the feature would share the incentives to see
> them fixed).

Another point in favor of removing that hack is this: `+` is not a valid character in Windows' filenames. It just so _happens_ that Cygwin (and therefore the MSYS2 Bash/`make` we use to compile Git for Windows) _pretends_ that it is a valid filename character, but regular Win32 programs cannot read/write such files, and it would preclude Git from being compiled with more native versions of a POSIX shell or `make`.

Ciao, Dscho