Spike - Can we use conda list and conda info all the info we need to work with conda

[DonJayamanne]

Can we stop using the environments.txt file?

Currently when we discover interpreter environments we walk through a list of locators. For conda we have CondaEnvService and CondaEnvFileService (in that order). CondaEnvService uses the conda command and CondaEnvFileService uses the .conda/environments.txt file. So this spike boils down to "can be get rid of CondaEnvFileService?"

Getting environments from mini conda does not work

• This could be a bigger problem. (possible it fails with vanilla installs of latest version of Conda)
  TODO:
• Need to test current extension on Windows, Mac and Linux.
  • Latest anaconda
  • Latest mini conda
  • Test discovery of conda environments (ensure they are listed in environment list)
• Try to find a better way e.g. conda run (check upstream on Conda repo for recommendations)

See https://github.com/microsoft/vscode-python/issues/6802 & #6854
This is Conda related.
TODO:

• We need to identify a better (proper way) to get this working
  (adding paths, etc is a hack and we're trying to get away from such hacks when dealing with Conda).

[DonJayamanne]

@brettcannon @karthiknadig Sorry, didn't manage to get to this (i.e. didn't investigate)

[karthiknadig]

On Windows:

Running conda info --all --json returns a JSON object that has a envs field. This value matches the contents of the ~/.conda/environments.txt

environments.txt

conda info --all --json

[DonJayamanne]

Running conda info --all --json returns a JSON object that has a envs field. This value matches the contents of the ~/.conda/environments.txt

Some background info for @karthiknadig.
Note: In the past conda info didn't return everything (at all).
Thats why the extension checked both places. Later PTVS too started doing the same thing.

So the question is, has conda fixed this and can we rely purely on conda info. If so, do this do this based on a version check?

[karthiknadig]

@DonJayamanne @luabud How far back in terms of anaconda versions are we supporting?

[DonJayamanne]

back in terms of anaconda versions are we supporting?

We need to check what versions are used by our users to make this decision.

[karthiknadig]

I looked up to a year back Anaconda3-5.3.0 released on September 27 2018. conda info gets the environments correctly.

[brettcannon]

The real trick is the conda version which is updated independently of Anaconda releases. And we have been planning to support at least conda 4.6 and newer due to relying on conda run going forward.

[karthiknadig]

So Anaconda3-5.3.0 uses conda 4.5.11. Since i can get environments on conda 4.5.11 using conda info i think we are are good there.

[karthiknadig]

On linux, tested from latest to Anaconda3-5.3.1 which uses conda 4.4.10. I am able to access environment data using conda list.

And via conda info:

If the minimum version we are planning to support is conda 4.6* then I think we can safely get rid of CondaEnvFileService.