Bug#995614: guile-3.0: Please build with --without-threads on alpha to fix FTBFS

John Paul Adrian Glaubitz <[email protected]> writes:

> Without --without-threads, guile would not build on SMP systems and even
> the built package would crash on SMP systems.
>
> If disabling threads would break the ABI, we could just rebuild the affected
> reverse dependencies on the builds using the normal binNMU method.

I've checked with upstream, and while they were not certain that
changing the --with-threads setting still breaks the library API, they
thought it probably did, which I believe means we have to assume that it
does (or could in the future), i.e. upstream makes no guarantees that
you can ever change that option without breaking the ABI.

Given that, I think we may have at least these constraints:

  - For any guile X.Y version (for a given arch) that's in a stable
    distribution (buster, bullseye, etc.) we cannot change the setting
    because it would break the contract and could crash existing debian
    and non-debian applications linked to the relevant guile-X.Y-libs.

  - For any X.Y version (for a given arch) that's only ever been in
    unstable/testing, we *could* break the ABI, but I think the bar
    should be reasonably high there, and I suspect we may want to
    discuss any plan along those lines a bit more broadly before
    deciding to pursue it (do we typically allow breaking SONAME
    compatibility in testing?), since plenty of people (including me)
    use the testing libs for real work.  In addition, as you say this
    would require rebuilding every reverse dependency.

Of course the best option, if it were feasbile, would be to just figure
out what's wrong and fix it.

Thanks