Installing pyenv and Python versions system-wide

[ktbarrett]

I followed #1843 and installed pyenv system-wide as root into /opt/pyenv/. I can then set PYENV_ROOT=/opt/pyenv, add pyenv's bin/ to the PATH and install Python versions as I see fit into this central location.

Now I need to set up venvs per user that use these Python executables. I can as a user set PYENV_ROOT=/opt/pyenv and add pyenv's bin/ to PATH and start issuing pyenv commands. Ultimately what I want to do is to run pyenv shell ${YOUR_PYTHON}; source ~/.venv/bin/active in each user's .profile.

The trouble is that I need to run eval "$(pyenv - bash)" before activating the Python version in the shell. This prints:

pyenv: cannot rehash: /opt/pyenv/shims isn't writable

But it otherwise seems to work. The Python version is sourced into the environment and I can make, modify, and use venvs in the user's HOME.

What is the rehash command doing? Is it important? Is there a way to silence this message? I'm thinking maybe the message being printed is expected to go out stderr, which is why there's the 2>/dev/null in the script, but it's actually going out stdout, so maybe this is a bug report.