Removing prefix injection breaks DLL loading if the Python DLL patch is missing

[travishathaway]

What is the idea?

This is the continuation of the work initially completed in this pull request:

• Resolve prefix injection #11666

To address issues brought up by this pull request (#11795 & #12161), we are currently entertaining different approaches to resolving, one of which may be reverting the changes. But first, we need better test coverage to prove we are doing the Right Things™️.

History

1. conda shell function injects $CONDA_PREFIX into $PATH causing incorrect behavior in conda run #11174
   • initial issue reported by VSCode/Microsoft
2. Remove base environment PATH components from conda run environment #11257
   • first attempt to fix the issue
   • doesn't remove the prefix injection that occurred on the shell interface level but removes the prefix injected (by the shell interface) just before executing the conda run script
   • discovered conda (de)activate didn't work as expected, specifically SHLVL 0 on Windows wasn't as untouched as expected (e.g., the %PATH% included more than just the condabin path)
   • identified 3 different cases of how environment activation should work Remove base environment PATH components from conda run environment #11257 (comment)
   • PR closed as it didn't solve the root problem
3. Resolve prefix injection #11666
   • second attempt to fix the issue
   • includes a detailed history of how the prefix injection code got added to conda in the first place Resolve prefix injection #11666 (comment)
   • discovered that the Python package on defaults and conda-forge both implement a DLL patch that made the prefix injection unnecessary
   • discovered that the DLL patch was missing in newer Python versions, this was corrected since the patch allows Python programs to run on Windows without activating the environment (an important nice to have)
   • PR merged as it removed complex shell-level code that complicated the Python code
4. CondaSSLError: OpenSSL appears to be unavailable on this machine. #11795 & Conda update failing on git bash (libmamba-solver issue) #12161
   • these issues arose due to Python 3.8/3.9 packaging issues on Windows
   • resolved with updated Python package patches
     • CondaSSLError: OpenSSL appears to be unavailable on this machine. #11795 (comment)
     • Fix win path 3.8 AnacondaRecipes/python-feedstock#83
     • Update 3.9 win2 AnacondaRecipes/python-feedstock#82

Other related issues

• Latest Miniconda Version fails installation if being installed to a path with >128 characters. #12250
  • Issues arose while installing latest miniconda
  • Affects deeply nested Linux install locations (> 127)
  • /usr/bin/env picks up on system Python and not conda Python

Tasks

#12240 (comment)

#12240 (comment)

#12240 (comment)

[kenodegard]

cc @mbargull @jezdez

[travishathaway]

I added a new issue under "Other related issues" that also show the side-effects of removing sys path injection:

• Latest Miniconda Version fails installation if being installed to a path with >128 characters. #12250

It's not directly related to DLLs, but I figured it would be good to group here.