Environment is not preserved per "project" (=directory), cannot override it from command line

[krassowski]

Description

I work on multiple projects using JupyterLab. Each time I re-open a project by using jlab path/to/project the environment gets reset to the last selected environment in any instance. Simply put the environment selector choice is global and there is nothing user can do to smoothly work on multiple projects.

Expected behavior

1. I would like to have an option to make the environment selection:

• a) global (as it currently is)
• b) directory-specific: this could be saved in a hidden file (which is a common practice, e.g. .vscode, .idea)

AND

2. I would like to have a command line option to manually specify the path to the environment.

As for the details of directory-specific hidden file, we should coordinate this with other parts of JupyterLab and possibly standardise support for the environment awareness too. I will open a separate issue and link this one.

Ultimately we would strive to get something like this: https://twitter.com/GaborCsardi/status/1532042947084095489