Bug#990994: llvm-12-tools cannot be installed for a foreign architecture

[Michel Dänzer]

On 2021-09-18 14:41, Helmut Grohne wrote:
> 
> So the real goal is cross building using clang I guess. Please correct
> me if that's wrong.

My main motivation for this bug report is only installing llvm-*-dev for foreign architectures, for cross building Mesa (in its upstream CI).

That said, cross building using clang might be useful for Mesa's CI in the future as well.


> I can immediately identify two problems with foreign installation of
> llvm-V-dev. That's certainly not exhaustive, but each of them is a
> show-stopper. It's the dependencies on llvm-V-tools and on llvm-V. The
> former was already evident from the bug report. The latter is an issue,
> because a foreign llvm-V-dev will pull a foreign llvm-V, which contains
> all the /usr/bin/llvm-*-V tools for a foreign architecture and we'll be
> unable to run them. So it might become installable, but in a useless
> way.

Not always useless. In particular, consider cases like installing llvm-*-dev:i386 on an amd64 host.

In Mesa's CI, it even works with ppc64el & s390x packages on amd64 hosts, by transparently running foreign binaries via qemu-user-static.


> Given the length of this mail, I guess nobody makes it to the end. I can
> write arbitrary nonsense here and nobody will notice.

Nice try. :)


-- 
Earthling Michel Dänzer            |                  https://redhat.com
Libre software enthusiast          |         Mesa and Xwayland developer