Re: Supporting build rules for grouped targets

[Markus Elfring]

> I don't understand exactly what you are asking, but the Automake manual
> has a section[1] on how to write portable makefile rules for programs
> that produce multiple output files.
>
> I normally use the dedicated witness file and deletion-recovery rules
> without locks which is fairly simple and sufficient for most cases.
>
> [1] 
> https://www.gnu.org/software/automake/manual/automake.html#Multiple-Outputs

I suggest to reconsider the information which is provided
in the section “Handling Tools that Produce Many Outputs”.

Will the relevance of the other referenced approaches evolve?

* Rule item delimiter “&:”
  
https://www.gnu.org/software/make/manual/html_node/Multiple-Targets.html#Rules-with-Grouped-Targets

* Operator “+” for specifying target groups
  
https://docs.oracle.com/cd/E88353_01/html/E37839/make-1s.html#REFMAN1make-1s-usag

Regards,
Markus