python-language-server: 'Too many open files' error coming from the server

Hi -

when I use pyls and pyls-mypy on a python file in Emacs everything works fine for a while. Documentation pops up, function signatures are shown inline, etc. Then, after perhaps a few dozen interactions I get the following (repeatable) error:

Error from the Language Server: jedi.api.environment.InvalidPythonEnvironment: Could not get version information for ’/Users/dkatz/.local/share/virtualenvs/lsp_example_project-cOuqdw3J/bin/python3.7’: OSError(24, ’Too many open files’) (Invalid Parameters) [16 times]

Once that error is raised, I see it every time the cursor hits any interesting piece of code. Note that I see this with two different LSP clients for Emacs (lsp-mode and eglot), so I suspect the problem is at the server.

I can trigger this behavior even with a completely trivial file like this:

import sys

by just moving the cursor on and off of sys several times (which I assume triggers communication with the server each time as it pops up the module information).

If I watch the number of python processes as a function of how I interact with the server I see something like this (taken from moving the cursor on and off of sys in the trivial file mentioned above):

event	effect	python processes
Open python file in Emacs		5
Put cursor on sys	pop up module info	13
Move cursor off sys	module info popup goes away	13
Put cursor back on sys	pop up module info	18
Move cursor off sys	module info goes away	19
Put cursor back on sys	pop up module info	23
Move cursor off sys	module info goes away	24
Put cursor back on sys	pop up module info	28
Move cursor off sys	module info goes away	29
Put cursor back on sys	pop up module info	34
Move cursor off sys	module info goes away	35
Put cursor back on sys	pop up module info	39
Move cursor off sys	module info goes away	40
Put cursor back on sys	pop up module info	44
Move cursor off sys	module info goes away	45
Put cursor back on sys	pop up module info	49
Move cursor off sys	module info goes away	50

and so on until I got the error with 81 python processes running. The number 81 seems to be pretty consistent for me - I get that number of processes with different files and different interactions (e.g. module info, function info, displaying function signatures, etc.)

Any ideas?

Thanks.

Dan

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Setup:

OS: macOS 10.13.6

Python: 3.7.0 Python package installer: pipenv Python packages:

• python-language-server 0.21.2 [all]
• pyls-mypy 0.1.3