On 08.11.18 13:43, Markus Armbruster wrote: > Philippe Mathieu-Daudé <f4...@amsat.org> writes: > >> Hi Markus, >> >> >> Le jeu. 8 nov. 2018 09:46, Markus Armbruster <arm...@redhat.com> a écrit : >> >>> Cleber Rosa <cr...@redhat.com> writes: >>> >>>> On 11/7/18 1:05 AM, Markus Armbruster wrote: > [...] >>>>> PEP 394 recommends software distributions install Python 3 into the >>>>> default path as python3, and users use that instead of python, except >>>>> for programs that are source compatible with both 2 and 3. So, is >>>>> finding out whether python is a Python 3 really appropriate? Why can't >>>>> we just use python3 and be done with it? >>>>> >>>> >>>> I mentioned that before, when you pointed out the issue you fix here, >>>> that configure may be the best place to get the Python version (not only >>>> the major version) and make it available elsewhere. Even if not used >>>> for other purposes, it is IMO important information to show on the >>>> resulting "configure" output. >>>> >>>> I'm sending patches to do that in a few. >>>> >>>>> If we can't: isn't this a configure problem? >>>>> >>>> >>>> I believe adhering to PEP394 is a good thing, but even that document >>>> recognizes that the real world is not a perfect place: "however, end >>>> users should be aware that python refers to python3 on at least Arch >>>> Linux". And it only covers *nix systems, so if we hope to care for >>>> non-*nix systems, we have to check the Python version manually. >>>> >>>> So, I guess the safest approach from QEMU's side is to check for the >>>> version indeed. >>> >>> If somebody can point to a system people still use where python3 doesn't >>> get you a Python 3, but python does, catering for such (crappy) systems >>> in configure makes sense. Until then, it's a waste of brain waves and >>> configure run time. >>> >>> PEP 394 mentions Arch Linux. It's been seven years. What's the most >>> recent version of Arch Linux that's still crappy in this regard? >>> >> >> Arch doesn't provide python2 by default, thus python points to python3. > > That's non-crappy as long as python3 also exists, as PEP 394 recommends. > Does it?
Sure it does. Arch is just problematic in how it handles "python" itself. I don't think there is any system that has Python 3 but no "python3". Max
