[pkg-uWSGI-devel] Bug#865224: uwsgi: ftbfs with multiple supported python3 versions

[Niko Tyni]

On Fri, Jun 30, 2017 at 10:28:09PM +0200, Jonas Smedegaard wrote:
> Quoting Scott Kitterman (2017-06-30 08:25:19)
> > On Tue, 20 Jun 2017 11:26:35 +1200 Michael Hudson-Doyle 
> > <michael.hudson at ubuntu.com> wrote:
> > > This may well turn out to be a cdbs bug in the end, but uwsgi does 
> > > not build when pysupport -r returns more than one version:
> > > 
> > > https://launchpadlibrarian.net/323025281/buildlog_ubuntu-artful-amd64.uwsgi_2.0.15-1ubuntu3_BUILDING.txt.gz
> > > 
> > > Picking out the failing lines:
> > > 
> > > *** asyncio_python27 plugin built and available in ./asyncio_python27_plugin.so ***
> > > touch debian/stamp-uwsgi-plugin-asyncio-python
> > > debian/rules:452: *** no python implementation resolved from flavor "python3.6" among packages python-uwsgidecorators python3-uwsgidecorators.  Stop.
> > > 
> > > In this build python 3.5 is the default and python 3.6 is supported. 
> > > In a build where python 3.6 is default and python 3.5 is supported, 
> > > the error complains about python 3.5 instead. And if python 3.6 is 
> > > the only supported version, the build completes successfully. So I 
> > > think this is really a problem in uwsgi or cdbs' handling of 
> > > multiple supported python versions.
> > 
> > We now have this in Debian, so bumping to serious.
> 
> Thanks, both for reporting initially and for bumping!

It looks like a cdbs issue to me,
  $(call cdbs_expand_pythonruntime,,python3.6)
breaks while
  $(call cdbs_expand_pythonruntime,,python3.5)
works (and results in "python3" as expected.)

A workaround that seems to help is putting
 X-Python3-Version: 3.5
in the Source paragraph of debian/control to prevent it from trying 3.6
at all. This makes the build work for me (but doesn't help the python3.6
transition of course.)

This is the worst blocker for the Perl 5.26 transition too (uwsgi needs
to be rebuilt because uwsgi-plugin-psgi links against libperl), so even
a temporary ugly workaround would be appreciated from this side :)
-- 
Niko Tyni   ntyni at debian.org