Re: make --shuffle

[Bruno Haible]

[CCing bug-gettext]

Hi Santiago,

> Long story short: I built all the packages in Debian unstable
> using make --shuffle and found more than 800 packages with
> Makefile issues, gettext being one of them:
> 
> In file included from ./log.c:24:
> ./gettextP.h:71:11: fatal error: libgnuintl.h: No such file or directory
>     71 | # include "libgnuintl.h"
>        |           ^~~~~~~~~~~~~~
> 
> Full log here:
> 
> https://people.debian.org/~sanvila/make-shuffle/build-logs/gettext_0.22.5-2_amd64-20241030T065521.940Z

I infer from
  - 
https://www.gnu.org/software/make/manual/html_node/Options-Summary.html#index-_002d_002dshuffle
  - https://trofi.github.io/posts/238-new-make-shuffle-mode.html
that
  - "make --shuffle" is a way to intentionally provoke failures by adding
    randomness,
  - "make --shuffle" assumes that the Makefile is ready for parallel execution
    (option -j).

In GNU, we *try* to support parallel make, see
https://www.gnu.org/prep/standards/html_node/Makefile-Basics.html
but there is no guarantee.

So, if you run into a "make -j4" failure, you are welcome to report it.
But reports produced with "make -j1000" or "make --shuffle" are not
realistic, and I will not investigate them. If you investigate them
and come up with a patch that is an obvious improvement, that's another
story, of course.

> Note: The above error only happened once after several tries during the last 
> months,
> so it's random. On the other hand it has all the signs of being a Makefile 
> bug.

Of course it's random, since "make --shuffle" is random by default.

Bruno