Feature Request: Toplevel Environment Variables

[swanysimon]

I'm using prek with monorepo support in a Python repository, where I have several projects managed by uv. I also am using mise-en-place to manage other tools in the repository, and have uv_auto_venv so that I don't have to prefix things with uv run. This is standard on the team. Project structure, simplified:

root/
  prek.toml
  project1/      <-- python 3.14
    pyproject.toml
    prek.toml
  project2/      <-- python 3.13
    pyproject.toml
    prek.toml

All projects have some variation of the following hooks:

[[repos]]
repo = "local"

[[repos.hooks]]
id = "ruff-format"
name = "format python"
entry = "uv run ruff format"
language = "system"
pass_filenames = false
files = '''
(?x)^(
  pyproject\.toml |
  uv\.lock |
  .*\.py
)$
'''
priority = 10

[[repos.hooks]]
id = "ruff-check"
name = "lint python"
entry = "uv run ruff check"
language = "system"
pass_filenames = false
files = '''
(?x)^(
  pyproject\.toml |
  uv\.lock |
  .*\.py
)$
'''
priority = 20

What we do is to only operate on one project at a time. So I cd into project1 and do my work. When my prek hooks run, they run just fine. But when I update my local branch by merging in changes that include project2, my pre-push hooks now run against that other project. Because I'm in a uv virtual environment, those checks fail.

Would it be possible/reasonable to have a global configuration to set environment variables? Right now what I do is specify at each hook level:

env = {
    UV_PYTHON = "",
    VIRTUAL_ENV = "",
}

This prevents uv from picking up the project1 virtual environment (warning) and Python version (error), but it's very annoying to put into every hook. Could there be a toplevel config option to set environment variables?