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

Hi,

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

Jeff King [off-list ref] writes:

quoted

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