Change project to virtual, `uv sync` still installs it

[j178]

Steps to reproduce

$ uv init project --lib
$ cd project
$ uv sync

$ cat pyproject.toml
[project]
name = "project"
version = "0.1.0"
description = "Add your description here"
readme = "README.md"
requires-python = ">=3.12"
dependencies = []

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

$ cat uv.lock
version = 1
requires-python = ">=3.12"

[[package]]
name = "project"
version = "0.1.0"
source = { editable = "." }

After removed the [build-system] section from pyproject.toml, the project should become virtual, but uv sync still build and installs the virtual project:

$ cat pyproject.toml
[project]
name = "project"
version = "0.1.0"
description = "Add your description here"
readme = "README.md"
requires-python = ">=3.12"
dependencies = []

$ uv sync -v
DEBUG uv 0.3.5
DEBUG Found project root: `/private/tmp/project`
DEBUG No workspace root found, using project root
DEBUG The virtual environment's Python version satisfies `Python >=3.12`
DEBUG Using request timeout of 30s
DEBUG Acquired lock for `/Users/Jo/.cache/uv/built-wheels-v3/editable/a0e7529ceb99aa48`
DEBUG Found static `pyproject.toml` for: project @ file:///private/tmp/project
DEBUG No workspace root found, using project root
DEBUG Existing `uv.lock` satisfies workspace requirements
Resolved 1 package in 5ms
DEBUG Using request timeout of 30s
DEBUG Requirement installed, but not fresh: project==0.1.0 (from file:///private/tmp/project)
DEBUG Identified uncached requirement: project @ file:///private/tmp/project
DEBUG Acquired lock for `/Users/Jo/.cache/uv/built-wheels-v3/editable/a0e7529ceb99aa48`
DEBUG Building: project @ file:///private/tmp/project
INFO Ignoring empty directory
DEBUG Solving with installed Python version: 3.12.5
DEBUG Adding direct dependency: setuptools>=40.8.0
DEBUG Found fresh response for: https://pypi.org/simple/setuptools/
DEBUG Searching for a compatible version of setuptools (>=40.8.0)
DEBUG Selecting: setuptools==74.0.0 [compatible] (setuptools-74.0.0-py3-none-any.whl)
DEBUG Found fresh response for: https://files.pythonhosted.org/packages/df/b5/168cec9a10bf93b60b8f9af7f4e61d526e31e1aad8b9be0e30837746d700/setuptools-74.0.0-py3-none-any.whl.metadata
DEBUG Tried 1 versions: setuptools 1
DEBUG Split specific environment resolution took 0.003s
DEBUG Installing in setuptools==74.0.0 in /Users/Jo/.cache/uv/builds-v0/.tmpJgiFHb
DEBUG Requirement already cached: setuptools==74.0.0
DEBUG Installing build requirement: setuptools==74.0.0
DEBUG Calling `setuptools.build_meta:__legacy__.get_requires_for_build_editable()`
DEBUG Calling `setuptools.build_meta:__legacy__.build_editable("/Users/Jo/.cache/uv/built-wheels-v3/editable/a0e7529ceb99aa48/cH78NBLJe7WJ1SJlYzd2P/.tmp6a6fqx", {}, None)`
DEBUG Finished building: project @ file:///private/tmp/project
Prepared 1 package in 579ms
DEBUG Uninstalled project (7 files, 1 directory)
Uninstalled 1 package in 0.87ms
Installed 1 package in 1ms
 ~ project==0.1.0 (from file:///private/tmp/project)

Environment

uv 0.3.5 (53ef633c6 2024-08-28) - the master tip
macOS 14.6.1 (23G93)

[zanieb]

I don't think our changes have released yet! #6585 is in the next release.

[zanieb]

Oh sorry I see "master tip" now.

[charliermarsh]

I can take a look at this.

[zanieb]

Presumably because the lockfile isn't treated as stale? (my naive guess haha)

[charliermarsh]

Probably yeah...

[charliermarsh]

Thank you for testing on main.