On Tue, Sep 17, 2019 at 03:57:26PM +0200, Kevin Wolf wrote: > Am 11.06.2019 um 19:12 hat Eduardo Habkost geschrieben: > > On Tue, Jun 11, 2019 at 05:07:55PM +0100, Peter Maydell wrote: > > > On Tue, 11 Jun 2019 at 17:03, Eduardo Habkost <ehabk...@redhat.com> wrote: > > > > > > > > On Tue, Jun 11, 2019 at 04:50:34PM +0100, Peter Maydell wrote: > > > > > On Mon, 10 Jun 2019 at 13:58, Peter Maydell > > > > > <peter.mayd...@linaro.org> wrote: > > > > > > Hi. This fails to build on one of my buildtest machines: > > > > > > > > > > > > ERROR: Cannot use 'python3', Python 2 >= 2.7 or Python 3 >= 3.5 is > > > > > > required. > > > > > > Use --python=/path/to/python to specify a supported Python. > > > > > > > > > > > > The machine has python 2.7.6 and 3.4.3. (It's an Ubuntu trusty > > > > > > box; it's one of the gcc compile farm machines so upgrades to its > > > > > > OS are not really under my control.) > > > > > > > > > > Rereading this, I realise that either the check or the error > > > > > message is wrong here. The machine has 2.7.6, which satisfies > > > > > "python 2 >= 2.7", so we should be OK to build. The bug > > > > > seems to be that we say "prefer python3 over plain python > > > > > on python2" early, but don't revisit that decision if the > > > > > python3 we found isn't actually good enough for us. > > > > > > > > Right. The error message is technically correct, but misleading. > > > > python3 is too old, but python2 would work. > > > > > > > > We can make configure not use python3 by default if it's too old, > > > > and fall back to python2 in this case. > > > > > > Sounds good. Since I have now managed to get my alternate > > > aarch64 box set up, how about I apply this pullreq and you > > > send a followup patch which does the fallback to python/python2 ? > > > > I will remove the python2/python3 patches and send a new pull > > request. > > What is the plan forward with this? Are the patches dropped for good? > > I think the plan was to drop Python 2 after QEMU 4.2, and then it > becomes really relevant what our minimum Python 3 version is. We've just > had another Python version discussion in the context of iotests (John > suggested using function annotations, but these are >= 3.5 only). > > Also, the fallback to Python 2 obviously makes no sense any more then, > so maybe it's not that important to add for a single QEMU release? > > As Peter seems to have indicated above that he found a replacement for > the test machine with an OS that isn't out of support, can we just > revive this patch as it is?
My plan is to remove Python 2 support in QEMU 4.2 (making the fallback to Python 2 a non-issue), and require Python >= 3.5. Now, even if my plan is rejected and we keep supporting Python 2 when building QEMU 4.2, my suggestion for the iotest maintainers is to make it require Python 3.5+ immediately, just like we do for tests/acceptance. I don't see why we should keep wasting our energy supporting ancient Python versions in a test suite that is not a requirement for building QEMU. -- Eduardo
