bug#35174: emacs-git sha f2d22273599f96a731e23b2f6d7571af8bb7bb3f fails to build

[Noam Postavsky <npostavs@gmail.com>]

>>> The weird part is that a previous(2019-Mar-24) emacs-git build, built
>>> with the same PKGBUILD worked fine, found and built lib/fcntl.c.
>>> - previous successful log build attached to this email
>> 
>> So I notice this successful build also is also printing the recursive
>> make invocation (and it seems to be running in parallel) whereas the
>> failing build just goes straight to printing the GEN lines.  I think
>> this all this points to some change in the build system on the server;
>> was 'make' updated recently?
>> 
>> make -C lib all
>> make info-real info-dir
>> make[1]: Entering directory '/build/emacs-git/src/emacs-git/lib'
>> make[1]: Entering directory '/build/emacs-git/src/emacs-git'
>> make -C doc/lispref info
>>   GEN      alloca.h
>>   GEN      dirent.h
>> 
>
> Not sure how make would switch from printing the recursive make
> invocation to printing GEN lines, since I've not touched the upstream
> emacs Makefile.

Hmm, but it's not the upstream emacs Makefile, because it's working fine
in other automated from scratch builds, e.g.:

https://hydra.nixos.org/jobset/gnu/emacs-trunk/evals (latest log as of
this writing is at
https://nix-cache.s3.amazonaws.com/log/4xpdrx48lfakc6piby1zihdmy9xcxyyp-emacs-tarball-unknown.drv)

> Since this build is running in a clean chroot, it will install,
> unattended, the latest available make version. (4.2.1)
>
> Looking at the git changes for the archlinux make pkg, the last version
> update was in 2018-11

And not make itself, since it hasn't changed since March when it worked
fine.  How mysterious.  Perhaps you could pass --debug to make and we
might get some more clues?