Allow per dependency build isolation for setup.py projects as well (#…

…6517)

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## Summary

<!-- What's the purpose of the change? What does it do, and why? -->

This changes the behavior a bit of the per-dependency build-isolation
override. That, if the dist name is known, it is passed into the
`SourceBuild::Setup` function. This allows for this override to work for
projects without a `pyproject.toml`, like `detectron2`, using the
specified requirement name. Previously only the `pyproject.toml` name
could be used, which these projects are lacking. An example of a
use-case is given in the *Test Plan* section.

Additionally, the `no_build_isolation_package` has been adding to
`InstallerSettingsRef` and used in `sync` and other commands, as this
was not done yet.

This is useful if you want to **non**-isolate a single package, even
ones without a proper `pyproject.toml`


## Test Plan

<!-- How was it tested? -->

With the following pyproject.toml.

```toml
[project]
name = "detectron-uv"
version = "0.1.0"
description = "Add your description here"
readme = "README.md"
requires-python = ">=3.12"
dependencies = [
    "detectron2",
    "setuptools",
    "torch",
]

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

[tool.uv.sources]
detectron2 = { git = "https://github.com/facebookresearch/detectron2", rev = "bcfd464d0c810f0442d91a349c0f6df945467143" }

[tool.uv]
no-build-isolation-package = ["detectron2"]
```

The package `detectron2` is now correctly **non**-isolated. Before,
because the logic depended on getting the name from the
`pyproject.toml`, which is lacking in detectron2 you would get the
message, that the source could not be built. This was because it would
still be *isolated* in that case.

With these changes you can now install using (given that you are inside
a workspace with a venv):

```
uv pip install torch setuptools
uv sync
```

This would previously fail with something like:

```
error: Failed to prepare distributions
  Caused by: Failed to fetch wheel: detectron2 @ git+https://github.com/facebookresearch/detectron2@bcfd464d0c810f0442d91a349c0f6df945467143
  Caused by: Build backend failed to determine extra requires with `build_wheel()` with exit status: 1
--- stdout:

--- stderr:
Traceback (most recent call last):
  File "<string>", line 14, in <module>
  File "/Users/tdejager/Library/Caches/uv/builds-v0/.tmptloDcZ/lib/python3.12/site-packages/setuptools/build_meta.py", line 332, in get_requires_for_build_wheel
    return self._get_build_requires(config_settings, requirements=[])
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/tdejager/Library/Caches/uv/builds-v0/.tmptloDcZ/lib/python3.12/site-packages/setuptools/build_meta.py", line 302, in _get_build_requires
    self.run_setup()
  File "/Users/tdejager/Library/Caches/uv/builds-v0/.tmptloDcZ/lib/python3.12/site-packages/setuptools/build_meta.py", line 502, in run_setup
    super().run_setup(setup_script=setup_script)
  File "/Users/tdejager/Library/Caches/uv/builds-v0/.tmptloDcZ/lib/python3.12/site-packages/setuptools/build_meta.py", line 318, in run_setup
    exec(code, locals())
  File "<string>", line 10, in <module>
ModuleNotFoundError: No module named 'torch'
---
  Caused by: This error likely indicates that detectron2 @ git+https://github.com/facebookresearch/detectron2@bcfd464d0c810f0442d91a349c0f6df945467143 depends on torch, but doesn't declare it as a build dependency. If detectron2 @ git+https://github.com/facebookresearch/detectron2@bcfd464d0c810f0442d91a349c0f6df945467143 is a first-party package, consider adding torch to its `build-system.requires`. Otherwise, `uv pip install torch` into the environment and re-run with `--no-build-isolation`.
  ```

**Edit**:

Some wording, used isolated where it should be **non**-isolated.

crates/uv-build/src/lib.rs

@@ -398,6 +398,7 @@ impl SourceBuild {
     pub async fn setup(
         source: &Path,
         subdirectory: Option<&Path>,
+        fallback_package_name: Option<&PackageName>,
         interpreter: &Interpreter,
         build_context: &impl BuildContext,
         source_build_context: SourceBuildContext,
@@ -422,10 +423,10 @@ impl SourceBuild {
         let (pep517_backend, project) =
             Self::extract_pep517_backend(&source_tree, &default_backend).map_err(|err| *err)?;
 
-        let package_name = project.clone().map(|p| p.name);
+        let package_name = project.as_ref().map(|p| &p.name).or(fallback_package_name);
 
         // Create a virtual environment, or install into the shared environment if requested.
-        let venv = if let Some(venv) = build_isolation.shared_environment(package_name.as_ref()) {
+        let venv = if let Some(venv) = build_isolation.shared_environment(package_name) {
             venv.clone()
         } else {
             uv_virtualenv::create_venv(
@@ -440,7 +441,7 @@ impl SourceBuild {
 
         // Setup the build environment. If build isolation is disabled, we assume the build
         // environment is already setup.
-        if build_isolation.is_isolated(package_name.as_ref()) {
+        if build_isolation.is_isolated(package_name) {
             let resolved_requirements = Self::get_resolved_requirements(
                 build_context,
                 source_build_context,
@@ -490,7 +491,7 @@ impl SourceBuild {
         // Create the PEP 517 build environment. If build isolation is disabled, we assume the build
         // environment is already setup.
         let runner = PythonRunner::new(concurrent_builds);
-        if build_isolation.is_isolated(package_name.as_ref()) {
+        if build_isolation.is_isolated(package_name) {
             create_pep517_build_environment(
                 &runner,
                 &source_tree,

crates/uv-dev/src/build.rs

@@ -98,6 +98,7 @@ pub(crate) async fn build(args: BuildArgs) -> Result<PathBuf> {
     let builder = SourceBuild::setup(
         &args.sdist,
         args.subdirectory.as_deref(),
+        None,
         python.interpreter(),
         &build_dispatch,
         SourceBuildContext::default(),

crates/uv-dispatch/src/lib.rs

@@ -298,11 +298,12 @@ impl<'a> BuildContext for BuildDispatch<'a> {
         dist: Option<&'data SourceDist>,
         build_kind: BuildKind,
     ) -> Result<SourceBuild> {
+        let dist_name = dist.map(distribution_types::Name::name);
         // Note we can only prevent builds by name for packages with names
         // unless all builds are disabled.
         if self
             .build_options
-            .no_build_requirement(dist.map(distribution_types::Name::name))
+            .no_build_requirement(dist_name)
             // We always allow editable builds
             && !matches!(build_kind, BuildKind::Editable)
         {
@@ -318,6 +319,7 @@ impl<'a> BuildContext for BuildDispatch<'a> {
         let builder = SourceBuild::setup(
             source,
             subdirectory,
+            dist_name,
             self.interpreter,
             self,
             self.source_build_context.clone(),