On Sun, Jul 21, 2019 at 9:15 AM Cameron Simpson <c...@cskk.id.au> wrote: > > On 21Jul2019 08:14, Chris Angelico <ros...@gmail.com> wrote: > >On Sun, Jul 21, 2019 at 5:26 AM Tim Daneliuk <i...@tundraware.com> wrote: > >> So, no, do NOT encode the hard location - ever. Always use env to > >> discover the one that > >> the user has specified. The only exception is /bin/sh which - for a > >> variety of reasons - > >> can reliably counted upon. > > > >A quick grep through my $PATH shows that there are a number of > >executable Python scripts there, including add-apt-repository, > >calibre, some lilypond stuff, trash-can management, samba-tool, iotop, > >and youtube-dl. If I have a venv active with, say, Python 3.9, then > >`/usr/bin/env python` is going to point to Python 3.9. What are the > >odds that all those scripts will work with Python 3.9 with no > >libraries installed? Why should typing "youtube-dl B7xai5u_tnk" be > >affected by a virtual environment, when typing "man youtube-dl" > >wouldn't be?? Using env for everything is a terrible idea and one that > >will basically make virtual environments useless. > > I'm with Tim Daneliuk. The environment matters and should be honoured > except in extremely weird cases. > > If you require a specific outcoming, set a specific environment. It is > under your control. Control it. > > For your specific example, "man youtube-dl" _is_ affected by the > environment. It honours the $MANPATH variable. > > For Peter J. Holzer, if we must play the "I've been doing this forever" > game: I've been sysadmining etc longer than your 25 years and disagree > with you. If your tools are strongly affected by version, run them with > an environment that finds the right version. > > Installers, particularly those run as root or in other low level setup > situations, should have a WELL DEFINED environment. > > If you have a tool that isn't portable, put it in a wrapper that coddles > its behaviour.
So.... you mean that a tool that depends on running on a consistent environment, it should use a shebang of "/usr/bin/python3.6" instead of "/usr/bin/env python3"? Because, wow, that would be exactly what is already happening on my system. Why use /usr/bin/env and then wrap something around it to force the environment, when you could just set a correct shebang so it properly defines its execution environment? ChrisA -- https://mail.python.org/mailman/listinfo/python-list
