Clear pythonfinder cache after Python install

[greysteil]

The issue

After a new Python version was installed by pyenv it was never found, because the old Pythons were cached.

The fix

Bust the cache after installing a new Python.

The checklist

• Associated issue (fixes Pyenv support broken since version 2018.10.09 ? #3136 again)
• A news fragment in the news/ directory to describe this fix with the extension .bugfix, .feature, .behavior, .doc. .vendor. or .trivial (this will appear in the release changelog). Use semantic line breaks and name the file after the issue number or the PR #.

[techalchemy]

Thanks!

[asmaier]

With pipenv, version 2018.11.26 I still see this behaviour:

$ pipenv install --dev
Warning: Python 3.6.5 was not found on your system…
Would you like us to install CPython 3.6.5 with pyenv? [Y/n]: Y
Installing CPython 3.6.5 with pyenv (this may take a few minutes)…
✔ Success! 

Warning: The Python you just installed is not available on your PATH, apparently.

At first it fails to recognise that Python 3.6.5 is already installed and available via pyenv. And second it then cannot find the installed version and stops the installation. Is this the issue that will be fixed by this commit discussed here?

[greysteil]

Yes! This should now be fixed - are you using 2018.11.26?

[asmaier]

Yes, I do. I just upgraded to the newest version with

brew upgrade pipenv pyenv

on Mac OS X 10.14.1.

$ pipenv --version
pipenv, version 2018.11.26
$ pyenv --version
pyenv 1.2.8

[greysteil]

Huh, and you're still seeing the problem with that setup? In that case I've no idea - it works for me on a relatively clean Docker container 🤔

[asmaier]

I also set the environment variable

$ env | grep pyenv
PYENV_ROOT=/Users/<myusername>/.pyenv

But pipenv refuses to interoperate with pyenv.

[techalchemy]

https://github.com/sarugaku/pythonfinder/pull/51/files#diff-963a50d451b089be9e0d078b9665eb01R91 will introduce a cleaner interface for clearing caches going forward

[techalchemy]

notably it also cuts runtimes down to ~1s

[kaprests]

With pipenv, version 2018.11.26 I still see this behaviour:

$ pipenv install --dev
Warning: Python 3.6.5 was not found on your system…
Would you like us to install CPython 3.6.5 with pyenv? [Y/n]: Y
Installing CPython 3.6.5 with pyenv (this may take a few minutes)…
✔ Success! 

Warning: The Python you just installed is not available on your PATH, apparently.

At first it fails to recognise that Python 3.6.5 is already installed and available via pyenv. And second it then cannot find the installed version and stops the installation. Is this the issue that will be fixed by this commit discussed here?

I also get this, but works as expected when reverting to version 2018.7.1.