Re: empty vs. reuse /usr/obj & /usr/tools for different crossbuilds?

[Steve Rikli <sr%genyosha.net@localhost>]

On Tue, Dec 09, 2025 at 07:58:12AM +0100, Martin Husemann wrote:
> On Mon, Dec 08, 2025 at 06:16:35PM -0800, Steve Rikli wrote:
> > Do I need to start with empty /usr/obj/ and /usr/tools/ directories for
> > this subsequent build? Or can I leave the amd64 x86_64 dirs in place?
> 
> The directory passed to -O has to be unique for the architecture,
> just apped the architecture to it, e.g. -O /usr/obj/amd64.

OK, I suspected something like that -- earlier this evening I tried
sharing /usr/obj/ among different arch crossbuild, and it failed.

I was looking through src/BUILDING in the meantime for hints about it,
and found this passage in the "-O obj" description:

    Note: The use of one of -M or -O is the only means of building
    multiple machine architecture userlands from the same source
    tree without cleaning between builds (in which case, one would
    specify distinct obj locations for each).

It doesn't spell it out quite as succinctly as you did, but still pretty
clear; it did lead me to think my attempt was likely not supported. :)

> The -T tooldir may be shared between architectures, as all the tools 
> have archtiecture-qualified names (or are identical, only specific to
> the host).

Good deal; that helps keep things simple in my setup. I'll adjust my
methods for /usr/obj/*/ and have another go at it.

Thanks,
sr.