[m-rev.] for review: Fix mmake issue when compiling without a bootstrap compiler.

[Peter Wang]

On Wed, 18 Oct 2023 20:34:43 +1100 Julien Fischer <jfischer at opturion.com> wrote:
> 
> On Wed, 18 Oct 2023, Peter Wang wrote:
> 
> > Fix an issue exposed by commit 7d001786a0d2b26a1cc6195fd63bd05b9843be03.
> >
> > VPATH indirectly refers to GRADESTRING_NO_TARGET.
> > When the VPATH is being calculated after the makefile is read,
> > the reference to GRADESTRING_NO_TARGET causes make to try to run the
> > Mercury compiler to output a grade string, but we may not yet have a
> > working Mercury compiler.
> >
> > scripts/Mmake.vars.in:
> >    Set EXTRA_INIT_DIRS_NO_TARGET to a non-empty string
> >    (that references GRADESTRING_NO_TARGET in a pattern substitution)
> >    only if EXTRA_LIB_DIRS is actually non-empty.
> 
> I think that will work; I suggest you commit it and we can see what
> effect it has on today's ROTD.

Ok, pushed.

Peter