Eglot, project.el, and python virtual environments

[Eric Abrahamsen]

Hi,

Here's another issue that's technically a emacs.help question, but might
result in some code/documentation updates, so I'm sending it here.

My main day-job code base is an AWS CloudFormation monstrosity involving
several Python Lambdas, among other things. Basic project structure
looks like:

project_root
├── .git
├── src
│   └── python
│       ├── VeryImportantLambda
│       │   └── .venv
│       ├── MoreImportance
│       │   └── .venv
│       ├── RunInCaseOfEmergency
│       │   └── .venv

I'm using the python-lsp-server python package in each Python
subdirectory, and the key is that each of those directories is a virtual
environment that needs to stay isolated from the others. Each has
different packages installed, and in some cases even the Python versions
are different (though I'm trying to get rid of that).

When I was using lsp-mode this wasn't difficult, because lsp-mode and
project.el are essentially orthogonal: if I visited a python file in a
given lambda directory, I could use `pyvenv-activate' to activate that
environment, and then the `lsp' invocation would confine itself to
python files within the environment. Project.el just provided
project-wide navigation.

Now I'm trying to move to Eglot, and there is tighter integration
between Eglot and project.el. Turning on Eglot in one lambda starts the
server for all Python libraries in the whole project, not just the
current environment. I looked into constructing my own version of the
call to `eglot', but it is tightly tied to a project, all the way down.

Is anyone else handling this situation? Any suggestions how to make it
work?

Thanks,
Eric