Re: New conditional assignment facility

[Jouke Witteveen]

On Mon, Jan 22, 2024 at 4:59 PM Martin Dorey
<Martin.Dorey@hitachivantara.com> wrote:
>
> Why is that?
>
>
> I imagine because that's how, to my surprise, it is today:
>
> martind@stormy:~/tmp/make-conditional-assignment-2024-01-22$ cat Makefile
> A := 42
> A += $(shell hello)
> martind@stormy:~/tmp/make-conditional-assignment-2024-01-22$ make
> make: hello: No such file or directory
> make: *** No targets.  Stop.
> martind@stormy:~/tmp/make-conditional-assignment-2024-01-22$
>
> ... and changing something so foundational sounds likely to cause widespread 
> issues.
>

As said before, += is going to be the exception (by respecting any
pre-existing variable type) because of legacy. That's not all that bad
though, it just exemplifies that variables can go from recursively
expanded to simply expanded, but not back.