Bug#951253: FTBFS with Boost 1.71

[Bas Couwenberg]

Control: tags -1 upstream
Control: forwarded -1 https://github.com/mapnik/mapnik/issues/4098

On 2020-02-13 11:08, Giovanni Mascellani wrote:
> your package fails to build with boost1.71. You can find a build log
> attached. If you want to attempt the build yourself, an updated version
> of boost-defaults which brings in boost1.71 dependencies can be found
> adding this line to your sources.list file:
> 
>   deb https://people.debian.org/~gio/reprepro gio main

Why isn't the new boost-defaults (also) in experimental?

> Apparently something changed in Boost.Spirit, and it doesn't like any
> more the way mapnik uses it. Unfortunately it is not easy for me,
> without knowing the code, understand how to prepare a patch for this.
> Apparently upstream has fixed compatibility with Boost 1.71 in master,
> but that patch is not released yet and it doesn't apply to the tree
> currently in Debian.

Thanks for looking into the upstream fix.

It seems Gentoo people already reported the issue for Boost 1.70:

  https://github.com/mapnik/mapnik/issues/4098

Which contains the comment:

"
  Boost Spirit 1.71 has a small bug which is fixed on 1.72
"

Can't we transition to 1.72 in Debian as well, or cherry-pick the spirit 
fix?

> I think the easiest solution would be to just package the next upstream
> version as soon as it is released. Do you have an idea on when this
> might happen? In the meantime, once Boost 1.71 is promoted to default,
> you can update your dependencies to explicitly use Boost 1.67, which
> will not be removed immediately from unstable (unless, of course, you
> want to write a patch for mapnik, but to me that seems a waste of 
> time).

Mapnik releases have become much more infrequent, there is not much 
demand for releases from Mapbox which uses development snapshots.

Based on the discussion in the upstream issue, we're likely able to 
cherry-pick the upstream commit to have 3.0.x build with boost1.72, but 
likely not with 1.71.

> However, the plan is to not release Boost 1.67 with bullseye, so I hope
> that upstream will release before Debian will. Do you think this is a
> viable plan?

If we can't get mapnik to work with the default boost in bullseye, we'll 
just not ship it and its rdeps.

While Mapnik is important to the OpenStreetMap project, I won't let it 
block progress in Debian.

Kind Regards,

Bas