Dear Pants community. My team and i use

mypy==0.91

for type checking. When my colleague runs

./pants typecheck <projects/project>

it works pretty well. When i run it, it will solve the constraints.txt file, and it takes 25+ mins. How come it runs so slowly on my computer?

That is a considerable amount of time. I assume you have similarly spec’ed machines, so it would perhaps come down to configuration. Do you have any custom config for pip or pants in your home directory, perhaps? Besides that nudge, I think I must defer to the experts, when they wake up 🙂

Yes, his might be a little faster, but not enough to justify this difference 🙂 We have a setup script that we run as

#!/usr/bin/env bash

set -euo pipefail

# You can change these constants.
PYTHON_BIN=python3.8
VIRTUALENV=.venv
PIP="${VIRTUALENV}/bin/pip"
CONSTRAINTS_FILE=constraints.txt

"${PYTHON_BIN}" -m venv "${VIRTUALENV}"

source .venv/bin/activate

echo "Installing pip"
"${PIP}" install pip --upgrade
echo "Installing poetry"
"${PIP}" install poetry
# Install all our requirements.txt, and also any 3rdparty
# dependencies specified outside requirements.txt, e.g. via a
# handwritten python_requirement_library target.
echo "Poetry update"
poetry update
echo "Installing dependencies"
"${PIP}" install -r <(poetry export --dev --without-hashes) -r <(./pants dependencies --type=3rdparty ::)
echo "Remove lockfile"
rm poetry.lock
echo "Generating constraints.txt"
rm constraints.txt
#pip uninstall pkg-resources==0.0.0 -y
pip list --format freeze  >> constraints.txt

And this should be the same for everyone using our monorepo

so you have the pkg-resources thing as well 🤔 what's that?

We have it too (though I've seen it seemingly flip between

pkg-resources

and

pkg_resources

🤔 )... https://stackoverflow.com/questions/39577984/what-is-pkg-resources-0-0-0-in-output-of-pip-freeze-command

Yes we have it too, and it seems like pants use it for repository structure, so it can not be uninstalled like i have shown above 😄

It's not a Pants thing. We use this script to manage our virtual environment (https://github.com/grapl-security/grapl/blob/main/build-support/manage_virtualenv.sh) and there's only a single pants command in it (

./pants dependencies --type=3rdparty ::

), which doesn't output anything about

pkg-resources

. We end up just filtering that out with a tasteful `grep -v`: https://github.com/grapl-security/grapl/blob/04f6869f723b353471f466c843a3f9c33e83171e/build-support/manage_virtualenv.sh#L59-L61

Does it do that 25 minute resolve every single time?

We work with

pants 2.7

And when pants has cached the constraints the constraints solving is fast. However if i rename a file, add a new one or a new dependency it all has to be redone. Will try what you posted above, when it finishes solving again 🙂

Ah, ok, so I'm trying to distinguish between two different possible issues: 1) Resolves are happening when you don't expect them to 2) Resolves only happen when you expect them to, but they take longer than you'd expect I thought you were saying 1) was the problem, but now it sounds like 2)? Or even both?

Yeah i would say a combination of the 2!

What would you expect to be a reasonable resolve time for your constraints file? For example can you time running

pip install -r constraints.txt

in a clean virtualenv?