Bug#1052382: sysprof: Should not build-depend on libunwind-dev on unsupported architectures

[Simon McVittie]

On Thu, 21 Sep 2023 at 09:58:01 +0200, John Paul Adrian Glaubitz wrote:
> src:sysprof build-depends on libunwind-dev unconditionally despite the fact that libunwind
> is not available on the following architectures: [several]

Does it make more sense to keep extending the current negative list of
architectures where libunwind isn't available, or would it be less churn
to turn it into a positive list of architectures where libunwind *is*
available? (Like src:gstreamer1.0 and src:efl do)

Or would it be possible to have an equivalent of the valgrind-if-available
package, so that dependent packages like sysprof and gstreamer1.0 don't
have to do their own tracking of the list of architectures where libunwind
is or isn't available, which will frequently be out of date?

Thanks,
    smcv