[Build-common-hackers] control substitution variables

[Colin Walters]

On Sun, 2003-06-15 at 23:58, Jeff Bailey wrote:
> How hard would it to throw some substitution variables in to control for
> the various modules.  I'm thinking something like being able to set the
> build-dep's automatically based on what modules the users included.

Yeah, I thought of this before, but there was some problem with it, I
forget exactly...

I think the main problem is that it introduces a sort of internal
circular dependency into the build process, because to know the build
deps you have to build the package, which requires knowing the
build-deps.  Now, the first time you build the package you can bootstrap
it because you know the Build-Depends, but if someone else wants to
rebuild your package from just the .diff.gz and the .orig.tar.gz they're
screwed.

Maybe this could be solved with a special debian/rules
compute-build-deps target, for which it is only required that
build-essential is installed.  Actually more generally it might be
useful to have an explicit step to generate debian/control from
debian/control.in or whatever.  Dunno, I haven't thought through all the
implications yet.