Satish Balay <[email protected]> writes: > On Sat, 18 Apr 2020, Satish Balay via petsc-dev wrote: > >> On Sat, 18 Apr 2020, Jed Brown wrote: >> >> > Satish Balay <[email protected]> writes: >> > >> > > Sure - the initial premise of this thread [as I understood] was: >> > > /usr/bin/python is python2. On python3 only installs - there is no >> > > /usr/bin/python (for ex: jedbrown/mpich-ccache docker file) - so we need >> > > to fix this issue in configure. >> > > >> > > I'm guessing that most installs will have /usr/bin/python as python2 or >> > > python3 - so missing /usr/bin/python is a smaller problem. Its not clear >> > > to me why this is missing in jedbrown/mpich-ccache - and how many OSes >> > > or distro will default to this mode. >> > >> > On Debian and Ubuntu, /usr/bin/python is part of python2; it isn't created >> > if you `apt install python3`. >> >> Ok - that a large userbase. >> >> So when python2 deprecated in debian - there won't be /usr/bin/python >> anymore? > > Also - debian does alternatives - don't know if they can setup a default > python [python2 vs python3] through this mechanism - and have anyone > installed as default. > > [for ex: I think if openmpi is installed /usr/bin/mpicc is automatically > setup as default via /etc/alternatives. I don't know if the same happens for > mpich]
Alternatives is meant for compatible implementations. Python2 and Python3 are not, so I doubt they will ever do that. This indicates that /usr/bin/python will not exist in the next release. https://wiki.debian.org/Python/2Removal I don't know what exactly that means. I'd guess it means one will need to use backports to get python2 if one really needs it; even so, I don't know if /usr/bin/python will exist. Perhaps only /usr/bin/python2. I don't know if they'll reintroduce /usr/bin/python at some release well in the future, but we should expect for it to not exist for a while.
