Re: [PATCH v2 3/4] Makefiles: change search through $(MAKEFLAGS) for GNU make 4.4

[Paul Smith <psmith@gnu.org>]

On Wed, 2022-11-30 at 13:28 +0900, Junio C Hamano wrote:
> I have to wonder how many projects they have broken with this change

Some, but not that many.  Most projects don't try to investigate
MAKEFLAGS, and of those that do many were already using the recommended
method, because even prior to GNU make 4.4 it was possible for
MAKEFLAGS to have stray "s" characters, in unusual situations (for
example if MAKEFLAGS were set in the makefile).

There were various bugs filed that various options could not be
investigated from within makefiles and also that running make from
within $(shell ...) didn't work right because MAKEFLAGS was not set.

It was just a mess, trying to keep the value of MAKEFLAGS set to
different values at different points in the processing of make.

Also, ensuring this trick for searching MAKEFLAGS continues to work
would have meant strictly controlling what new options we could add to
GNU make.  I haven't seen any other project use the filter-out --%
trick that the Git makefiles do, but even with that it won't help if a
new single-letter option that takes an argument is added.