Thanks for this! I have been putting off moving from pip to poetry (in order to circumvent pips many limitations) due to poetrys many limitations. uv looks like my journey may finally come to an end. One issue, though:

C:\Code\TestParent\pyproject.toml

[project]
name = "TestParent"
version = "0"
description = ""
authors = []
dependencies = ["TestChild @ file:///${PROJECT_ROOT}/TestChild"]

C:\Code\TestParent\TestChild\pyproject.toml

[project]
name = "TestChild"
version = "0"
description = ""
authors = []

(.venv) C:\Code\TestParent>uv --version
uv 0.1.3

(.venv) C:\Code\TestParent>uv pip install -e .
   Built file:///C:/Code/TestParent                                                                                                                                                                 Built 1 editable in 2.06s
error: Package `testchild` attempted to resolve via URL: file:///C:/Code/TestParent/TestChild. URL dependencies must be expressed as direct requirements or constraints. Consider adding `testchild @ file:///C:/Code/TestParent/TestChild` to your dependencies or constraints file.

Maybe I misunderstand "dependencies or constraints file", but I thought pyproject.toml was that file, and it includes (not exactly, but semantically) what is requested. The test case which issues the

URL dependencies must be expressed as direct requirements or constraints

error has a transitive URL dependency (URL package depending on another URL package), in which case I understand the warning; I do not understand it in my case.