I'd like to make the GCC 6 defaults change later this week(end), including icu 57 and boost 1.61 transitions.
While the bug number of the GCC 6 related issues is still high, I'm proposing to fix these on the fly (as suggested/discussed with Nils), because many of the symbols related build failures are better to fix once GCC 6 is the new default (and a number of packages not yet building using GCC 6 are already removed from testing). icu 57 should be included in this transition, because it's a dependency of boost; it's already tracked in a separate issue #819530. GCC 6 has a fix for a libstdc++ ABI symbol mangling issue which is present in GCC 5 [1], and which is triggered by boost code. The good thing is that boost always changes it's soname with a new release, so we have a clean transition (#833377). I'm not yet aware of other libraries affected by this issue, all other changes to symbols seem to be the usual dropped/added template related symbols. If we find other libraries affected by this issue, we'll have to do the usual library renaming dance (or using a new upstream with a different soname). The issue shows as a link error, looking for a cxx11 symbol which is not found in a library built by GCC 5. So the idea is to upload to unstable: - gcc-defaults pointing to GCC 6 - icu 57 (as already in experimental). doesn't matter if it is built using GCC 5 or GCC 6 - upload boost1.61 to unstable b-d on icu 57 and GCC 6 - upload boost-defaults to unstable - make sure the new gcc-defaults is available on the buildds - start the binNMUs for icu and boost. - finish fixing GCC 6 releated ftbfs - remove boost1.58 and boost1.60 - remove GCC 5 Matthias [1] https://gcc.gnu.org/ml/gcc-patches/2016-04/msg00314.html
