On 26.10.19 22:09, Rebecca N. Palmer wrote:
What should be done with modules where Python 3.8 compatibility requires moving to a new upstream release that doesn't support Python 2, but the Python 2 package still has dependencies (so can't be removed yet under existing rules)?- Split them into two source packages with different upstream versions, as was done for matplotlib and numpy?- Remove the Python 2 package anyway? - Let them be broken in Python 3.8 for now?e.g. pandas dropped python2 support in 0.25.0, and gained python3.8 support in 0.25.2:https://github.com/pandas-dev/pandas/issues/29043
yes, that will be an ongoing problem, I see the same for pillow (latest 2.7 supporting release is 6.2.1) and numpy (1.16 not supporting 3.8, and 1.17 not supporting 2.7).
Ubuntu got pandas 0.23 to build with python3.8, but only by ignoring 268 test failures (I haven't yet had time to assess their severity):https://bugs.launchpad.net/ubuntu/+source/pandas/+bug/1849374https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-focal/focal/amd64/p/pandas/20191024_181815_7c017@/log.gz
yes, https://bugs.launchpad.net/bugs/1849374 documents where I ignored test results for a first build, and numpy test results are ignored as well due to a packaging bug.
Ubuntu already dropped python-pandas, I wasn't involved with that. So this should be possible to do. Please ask Steve Langasek for details. In the case for pandas it should be possible to remove it now with some work, avoiding a second Pandas source.
Having a first build in the archive allows you to get more packages built, and more people working on the stack. For example the whole astropy stack builds and passes tests (except astropy itself). So there is value. Lets enable to build stuff first for 3.8 as a supported non-default option.