Environments and dependency version specifiers don't work with workspaces

[chadrik]

I ran into an issue with locking and version specifiers similar to #4668 and #4669, but the fix there of creating environments for different python versions does not work with workspaces.

Here's how I reproduced this.

I started with this pyproject.toml and confirmed that it works with uv==0.4.17

[project]
name = "foo"
version = "0.1.0"
description = "Add your description here"
readme = "README.md"
requires-python = ">=3.7"
dependencies = [
    "types-psutil==6.0.0.20240901 ; python_version >= '3.8'",
]

[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

[tool.uv]
environments = ["python_version < '3.8'", "python_version >= '3.8'"]

$ uv lock
Using CPython 3.8.19 interpreter at: /usr/local/opt/[email protected]/bin/python3.8
Resolved 2 packages in 3ms

Note that this requires the tool.uv.environment setting recommended in #4668

Next I setup my repo using workspaces, with a folder structure like this:

./
  project-foo/
    pyproject.toml
  pyproject.toml

The root pyproject.toml looks like this:

[tool.uv.workspace]
members = [
    "project-foo",
]

[tool.uv.sources]
foo = { workspace = true }

[tool.uv]
environments = ["python_version < '3.8'", "python_version >= '3.8'"]

The child looks like this (same as before but without the uv.tool.environment setting):

[project]
name = "foo"
version = "0.1.0"
description = "Add your description here"
readme = "README.md"
requires-python = ">=3.7"
dependencies = [
    "types-psutil==6.0.0.20240901 ; python_version >= '3.8'",
]

[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

[tool.uv]
environments = ["python_version < '3.8'", "python_version >= '3.8'"]

Locking from the root of the workspace fails:

$ uv lock
Using CPython 3.8.19 interpreter at: /usr/local/opt/[email protected]/bin/python3.8
  × No solution found when resolving dependencies:
  ╰─▶ Because the requested Python version (>=3.7) does not satisfy Python>=3.8 and your project depends on types-psutil{python_full_version
      >= '3.8'}==6.0.0.20240901, we can conclude that your project's requirements are unsatisfiable.

I made a repo to demonstrate: https://github.com/chadrik/uv-tests

These are some PRs mentioned that could be related:

• Fork resolution when Python requirement is narrowed #4712
• fork every time we see a non-trivial marker ("aggressive" forking) #6143

Is there a way to indicate that a dependency simply should not be installed on certain versions of python?

[charliermarsh]

Thanks. That repo is 404ing for me -- any chance the URL is not quite right?

[charliermarsh]

(Working now.)

[charliermarsh]

Ah sorry. You need to add a [project] table to the root pyproject.toml:

diff --git a/pyproject.toml b/pyproject.toml
index 504c40f..f0b42da 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,3 +1,7 @@
+[project]
+name = "root"
+version = "0.0.1"
+
 [tool.uv.workspace]
 members = [
     "project-foo",

[charliermarsh]

I'll lift this restriction.