On Fri, Jan 10, 2020 at 11:49 AM Isuru Fernando <isu...@gmail.com> wrote: > > > On Fri, Jan 10, 2020 at 3:53 PM E. Madison Bray <erik.m.b...@gmail.com> wrote: >> >> On Fri, Jan 10, 2020 at 10:41 AM Timo Kaufmann <eisfre...@gmail.com> wrote: >> > >> > I have said this before, but I feel like the point was dropped out of the >> > discussion so I'll stress it again. The major issue here is *not* the >> > compatibility of sage's own codebase. A few "from __future__ import"'s are >> > not so bad. >> > >> > The issue is that python2 compatibility forces us to use outdated versions >> > of a lot of libraries, since many libraries have dropped python2 support a >> > while ago. This is a big headache especially for packagers. Those outdated >> > libraries are generally not available on distros. At the same time sage is >> > usually not compatible with the newer versions. Sage is already difficult >> > to package, and that makes it a lot more difficult. >> >> Can you be more specific about this? What is it about Sage's upstream >> codebase maintaining backwards-compatibility for Python 2 that >> prevents you from packaging it for Python 3 only, given that it does >> support Python 3? No one is saying that just because upstream support >> is maintained for Python 2 for one or two (at the most) more releases, >> any downstream packagers have to package it for Python 2. > > > I'll give an example. sage has rpy2 2.8.2. > rpy2 latest is 3.2.4 but 3.x series is python 3 only and sage requires > breaking changes to support rpy2 3.x. See > https://trac.sagemath.org/ticket/28494#comment:6 > While python2 support for rpy2 is required, sage codebase can't be updated to > 3.x (unless someone adds code to detect rpy2 version and support both 2.8.2 > and 3.2.4)
That seems like the obvious approach to me. As it is I've long felt that Sage should be more flexible in its dependencies where possible/necessary. With most Python packages it's easy as most have a <package>.__version__ and its not so hard to define some variable like IS_RPY_2 and just have two separate branches. I have things like that all over the place in other packages to support e.g. different Numpy versions or work around version-specific bugs. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/CAOTD34a9wVPCu7LPcH_onCvCaViY70dSUH-DJxR1M5PbHYS%2BFQ%40mail.gmail.com.
