Merge b2caf475a0 into f609e1ddaf

crates/uv-bench/benches/uv.rs

@@ -103,7 +103,7 @@ mod resolver {
         ResolverEnvironment, ResolverOutput,
     };
     use uv_types::{BuildIsolation, EmptyInstalledPackages, HashStrategy};
-    use uv_workspace::WorkspaceCache;
+    use uv_workspace::{WorkspaceCache, pyproject::ExtraBuildDependencies};
 
     static MARKERS: LazyLock<MarkerEnvironment> = LazyLock::new(|| {
         MarkerEnvironment::try_from(MarkerEnvironmentBuilder {
@@ -141,6 +141,7 @@ mod resolver {
         universal: bool,
     ) -> Result<ResolverOutput> {
         let build_isolation = BuildIsolation::default();
+        let extra_build_dependencies = ExtraBuildDependencies::default();
         let build_options = BuildOptions::default();
         let concurrency = Concurrency::default();
         let config_settings = ConfigSettings::default();
@@ -185,6 +186,7 @@ mod resolver {
             IndexStrategy::default(),
             &config_settings,
             build_isolation,
+            &extra_build_dependencies,
             LinkMode::default(),
             &build_options,
             &hashes,

crates/uv-build-frontend/src/lib.rs

@@ -42,6 +42,7 @@ use uv_static::EnvVars;
 use uv_types::{AnyErrorBuild, BuildContext, BuildIsolation, BuildStack, SourceBuildTrait};
 use uv_warnings::warn_user_once;
 use uv_workspace::WorkspaceCache;
+use uv_workspace::pyproject::ExtraBuildDependencies;
 
 pub use crate::error::{Error, MissingHeaderCause};
 
@@ -281,6 +282,7 @@ impl SourceBuild {
         workspace_cache: &WorkspaceCache,
         config_settings: ConfigSettings,
         build_isolation: BuildIsolation<'_>,
+        extra_build_dependencies: &ExtraBuildDependencies,
         build_stack: &BuildStack,
         build_kind: BuildKind,
         mut environment_variables: FxHashMap<OsString, OsString>,
@@ -297,7 +299,6 @@ impl SourceBuild {
         };
 
         let default_backend: Pep517Backend = DEFAULT_BACKEND.clone();
-
         // Check if we have a PEP 517 build backend.
         let (pep517_backend, project) = Self::extract_pep517_backend(
             &source_tree,
@@ -305,6 +306,7 @@ impl SourceBuild {
             fallback_package_name,
             locations,
             source_strategy,
+            extra_build_dependencies,
             workspace_cache,
             &default_backend,
         )
@@ -506,6 +508,7 @@ impl SourceBuild {
         package_name: Option<&PackageName>,
         locations: &IndexLocations,
         source_strategy: SourceStrategy,
+        extra_build_dependencies: &ExtraBuildDependencies,
         workspace_cache: &WorkspaceCache,
         default_backend: &Pep517Backend,
     ) -> Result<(Pep517Backend, Option<Project>), Box<Error>> {
@@ -517,17 +520,24 @@ impl SourceBuild {
                 let pyproject_toml: PyProjectToml =
                     PyProjectToml::deserialize(pyproject_toml.into_deserializer())
                         .map_err(Error::InvalidPyprojectTomlSchema)?;
+                let name = pyproject_toml
+                    .project
+                    .as_ref()
+                    .map(|project| &project.name)
+                    .or(package_name);
+                let extra_build_dependencies = name
+                    .as_ref()
+                    .and_then(|name| extra_build_dependencies.get(name).cloned())
+                    .unwrap_or_default();
+
+                let backend = if let Some(mut build_system) = pyproject_toml.build_system {
+                    // Apply extra-build-dependencies if there are any
+                    build_system.requires.extend(extra_build_dependencies);
 
-                let backend = if let Some(build_system) = pyproject_toml.build_system {
                     // If necessary, lower the requirements.
                     let requirements = match source_strategy {
                         SourceStrategy::Enabled => {
-                            if let Some(name) = pyproject_toml
+                            if let Some(name) = name {
-                                .project
-                                .as_ref()
-                                .map(|project| &project.name)
-                                .or(package_name)
-                            {
                                 let build_requires = uv_pypi_types::BuildRequires {
                                     name: Some(name.clone()),
                                     requires_dist: build_system.requires,
@@ -606,7 +616,13 @@ impl SourceBuild {
                             );
                         }
                     }
-                    default_backend.clone()
+                    let mut backend = default_backend.clone();
+                    // Apply extra_build_dependencies
+                    // TODO(Gankra): should Sources/Indexes be applied on this path?
+                    backend
+                        .requirements
+                        .extend(extra_build_dependencies.into_iter().map(Requirement::from));
+                    backend
                 };
                 Ok((backend, pyproject_toml.project))
             }
@@ -617,12 +633,21 @@ impl SourceBuild {
                         source_tree.to_path_buf(),
                     )));
                 }
-
                 // If no `pyproject.toml` is present, by default, proceed with a PEP 517 build using
                 // the default backend, to match `build`. `pip` uses `setup.py` directly in this
                 // case,  but plans to make PEP 517 builds the default in the future.
                 // See: https://github.com/pypa/pip/issues/9175.
-                Ok((default_backend.clone(), None))
+                let mut backend = default_backend.clone();
+                // Apply extra_build_dependencies
+                // TODO(Gankra): should Sources/Indexes be applied on this path?
+                let extra_build_dependencies = package_name
+                    .as_ref()
+                    .and_then(|name| extra_build_dependencies.get(name).cloned())
+                    .unwrap_or_default();
+                backend
+                    .requirements
+                    .extend(extra_build_dependencies.into_iter().map(Requirement::from));
+                Ok((backend, None))
             }
             Err(err) => Err(Box::new(err.into())),
         }

crates/uv-cli/src/options.rs

@@ -323,6 +323,7 @@ pub fn resolver_options(
             .map(|config_settings| config_settings.into_iter().collect::<ConfigSettings>()),
         no_build_isolation: flag(no_build_isolation, build_isolation, "build-isolation"),
         no_build_isolation_package: Some(no_build_isolation_package),
+        extra_build_dependencies: None,
         exclude_newer,
         link_mode,
         no_build: flag(no_build, build, "build"),
@@ -434,6 +435,7 @@ pub fn resolver_installer_options(
         } else {
             Some(no_build_isolation_package)
         },
+        extra_build_dependencies: None,
         exclude_newer,
         link_mode,
         compile_bytecode: flag(compile_bytecode, no_compile_bytecode, "compile-bytecode"),

crates/uv-dispatch/src/lib.rs

@@ -40,6 +40,7 @@ use uv_types::{
     HashStrategy, InFlight,
 };
 use uv_workspace::WorkspaceCache;
+use uv_workspace::pyproject::ExtraBuildDependencies;
 
 #[derive(Debug, Error)]
 pub enum BuildDispatchError {
@@ -88,6 +89,7 @@ pub struct BuildDispatch<'a> {
     shared_state: SharedState,
     dependency_metadata: &'a DependencyMetadata,
     build_isolation: BuildIsolation<'a>,
+    extra_build_dependencies: &'a ExtraBuildDependencies,
     link_mode: uv_install_wheel::LinkMode,
     build_options: &'a BuildOptions,
     config_settings: &'a ConfigSettings,
@@ -114,6 +116,7 @@ impl<'a> BuildDispatch<'a> {
         index_strategy: IndexStrategy,
         config_settings: &'a ConfigSettings,
         build_isolation: BuildIsolation<'a>,
+        extra_build_dependencies: &'a ExtraBuildDependencies,
         link_mode: uv_install_wheel::LinkMode,
         build_options: &'a BuildOptions,
         hasher: &'a HashStrategy,
@@ -135,6 +138,7 @@ impl<'a> BuildDispatch<'a> {
             index_strategy,
             config_settings,
             build_isolation,
+            extra_build_dependencies,
             link_mode,
             build_options,
             hasher,
@@ -433,6 +437,7 @@ impl BuildContext for BuildDispatch<'_> {
             self.workspace_cache(),
             self.config_settings.clone(),
             self.build_isolation,
+            self.extra_build_dependencies,
             &build_stack,
             build_kind,
             self.build_extra_env_vars.clone(),

crates/uv-settings/src/combine.rs

@@ -1,5 +1,5 @@
-use std::num::NonZeroUsize;
 use std::path::PathBuf;
+use std::{collections::BTreeMap, num::NonZeroUsize};
 
 use url::Url;
 
@@ -120,6 +120,21 @@ impl<T> Combine for Option<Vec<T>> {
     }
 }
 
+impl<K: Ord, T> Combine for Option<BTreeMap<K, Vec<T>>> {
+    /// Combine two maps of vecs by combining their vecs
+    fn combine(self, other: Option<BTreeMap<K, Vec<T>>>) -> Option<BTreeMap<K, Vec<T>>> {
+        match (self, other) {
+            (Some(mut a), Some(b)) => {
+                for (key, value) in b {
+                    a.entry(key).or_default().extend(value);
+                }
+                Some(a)
+            }
+            (a, b) => a.or(b),
+        }
+    }
+}
+
 impl Combine for Option<ConfigSettings> {
     /// Combine two maps by merging the map in `self` with the map in `other`, if they're both
     /// `Some`.

crates/uv-settings/src/settings.rs

@@ -20,7 +20,7 @@ use uv_redacted::DisplaySafeUrl;
 use uv_resolver::{AnnotationStyle, ExcludeNewer, ForkStrategy, PrereleaseMode, ResolutionMode};
 use uv_static::EnvVars;
 use uv_torch::TorchMode;
-use uv_workspace::pyproject_mut::AddBoundsKind;
+use uv_workspace::{pyproject::ExtraBuildDependencies, pyproject_mut::AddBoundsKind};
 
 /// A `pyproject.toml` with an (optional) `[tool.uv]` section.
 #[allow(dead_code)]
@@ -371,6 +371,7 @@ pub struct ResolverOptions {
     pub no_binary_package: Option<Vec<PackageName>>,
     pub no_build_isolation: Option<bool>,
     pub no_build_isolation_package: Option<Vec<PackageName>>,
+    pub extra_build_dependencies: Option<ExtraBuildDependencies>,
     pub no_sources: Option<bool>,
 }
 
@@ -611,6 +612,20 @@ pub struct ResolverInstallerOptions {
     "#
     )]
     pub no_build_isolation_package: Option<Vec<PackageName>>,
+    /// Additional build dependencies for dependencies.
+    ///
+    /// This is intended for enabling more packages to be built with
+    /// build-isolation, by adding dependencies that they ambiently
+    /// assume to exist (`setuptools` and `pip` being common).
+    #[option(
+        default = "[]",
+        value_type = "dict",
+        example = r#"
+        [extra-build-dependencies] 
+        pytest = ["setuptools"]
+    "#
+    )]
+    pub extra_build_dependencies: Option<ExtraBuildDependencies>,
     /// Limit candidate packages to those that were uploaded prior to a given point in time.
     ///
     /// Accepts a superset of [RFC 3339](https://www.rfc-editor.org/rfc/rfc3339.html) (e.g.,
@@ -1107,6 +1122,20 @@ pub struct PipOptions {
         "#
     )]
     pub no_build_isolation_package: Option<Vec<PackageName>>,
+    /// Additional build dependencies for dependencies.
+    ///
+    /// This is intended for enabling more packages to be built with
+    /// build-isolation, by adding dependencies that they ambiently
+    /// assume to exist (`setuptools` and `pip` being common).
+    #[option(
+        default = "[]",
+        value_type = "dict",
+        example = r#"
+            [extra-build-dependencies]
+            pytest = ["setuptools"]
+        "#
+    )]
+    pub extra_build_dependencies: Option<ExtraBuildDependencies>,
     /// Validate the Python environment, to detect packages with missing dependencies and other
     /// issues.
     #[option(
@@ -1661,6 +1690,7 @@ impl From<ResolverInstallerOptions> for ResolverOptions {
             no_binary_package: value.no_binary_package,
             no_build_isolation: value.no_build_isolation,
             no_build_isolation_package: value.no_build_isolation_package,
+            extra_build_dependencies: value.extra_build_dependencies,
             no_sources: value.no_sources,
         }
     }
@@ -1716,6 +1746,7 @@ pub struct ToolOptions {
     pub config_settings: Option<ConfigSettings>,
     pub no_build_isolation: Option<bool>,
     pub no_build_isolation_package: Option<Vec<PackageName>>,
+    pub extra_build_dependencies: Option<ExtraBuildDependencies>,
     pub exclude_newer: Option<ExcludeNewer>,
     pub link_mode: Option<LinkMode>,
     pub compile_bytecode: Option<bool>,
@@ -1743,6 +1774,7 @@ impl From<ResolverInstallerOptions> for ToolOptions {
             config_settings: value.config_settings,
             no_build_isolation: value.no_build_isolation,
             no_build_isolation_package: value.no_build_isolation_package,
+            extra_build_dependencies: value.extra_build_dependencies,
             exclude_newer: value.exclude_newer,
             link_mode: value.link_mode,
             compile_bytecode: value.compile_bytecode,
@@ -1772,6 +1804,7 @@ impl From<ToolOptions> for ResolverInstallerOptions {
             config_settings: value.config_settings,
             no_build_isolation: value.no_build_isolation,
             no_build_isolation_package: value.no_build_isolation_package,
+            extra_build_dependencies: value.extra_build_dependencies,
             exclude_newer: value.exclude_newer,
             link_mode: value.link_mode,
             compile_bytecode: value.compile_bytecode,
@@ -1824,6 +1857,7 @@ pub struct OptionsWire {
     config_settings: Option<ConfigSettings>,
     no_build_isolation: Option<bool>,
     no_build_isolation_package: Option<Vec<PackageName>>,
+    extra_build_dependencies: Option<ExtraBuildDependencies>,
     exclude_newer: Option<ExcludeNewer>,
     link_mode: Option<LinkMode>,
     compile_bytecode: Option<bool>,
@@ -1940,6 +1974,7 @@ impl From<OptionsWire> for Options {
             sources,
             default_groups,
             dependency_groups,
+            extra_build_dependencies,
             dev_dependencies,
             managed,
             package,
@@ -1979,6 +2014,7 @@ impl From<OptionsWire> for Options {
                 config_settings,
                 no_build_isolation,
                 no_build_isolation_package,
+                extra_build_dependencies,
                 exclude_newer,
                 link_mode,
                 compile_bytecode,

crates/uv-workspace/src/pyproject.rs

@@ -374,6 +374,21 @@ pub struct ToolUv {
     )]
     pub dependency_groups: Option<ToolUvDependencyGroups>,
 
+    /// Additional build dependencies for dependencies.
+    ///
+    /// This is intended for enabling more packages to be built with
+    /// build-isolation, by adding dependencies that they ambiently
+    /// assume to exist (`setuptools` and `pip` being common).
+    #[option(
+        default = "[]",
+        value_type = "dict",
+        example = r#"
+            [tool.uv.extra-build-dependencies]
+            pytest = ["pip"]
+        "#
+    )]
+    pub extra_build_dependencies: Option<ToolUvExtraBuildDependencies>,
+
     /// The project's development dependencies.
     ///
     /// Development dependencies will be installed by default in `uv run` and `uv sync`, but will
@@ -745,6 +760,70 @@ pub struct DependencyGroupSettings {
     pub requires_python: Option<VersionSpecifiers>,
 }
 
+pub type ExtraBuildDependencies =
+    BTreeMap<PackageName, Vec<uv_pep508::Requirement<VerbatimParsedUrl>>>;
+
+#[derive(Default, Debug, Clone, PartialEq, Eq)]
+#[cfg_attr(test, derive(Serialize))]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct ToolUvExtraBuildDependencies(ExtraBuildDependencies);
+
+impl ToolUvExtraBuildDependencies {
+    /// Returns the underlying `BTreeMap` of group names to settings.
+    pub fn inner(&self) -> &ExtraBuildDependencies {
+        &self.0
+    }
+
+    /// Convert the [`ToolUvExtraBuildDependencies`] into its inner `BTreeMap`.
+    #[must_use]
+    pub fn into_inner(self) -> ExtraBuildDependencies {
+        self.0
+    }
+}
+
+/// Ensure that all keys in the TOML table are unique.
+impl<'de> serde::de::Deserialize<'de> for ToolUvExtraBuildDependencies {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        struct DependenciesVisitor;
+
+        impl<'de> serde::de::Visitor<'de> for DependenciesVisitor {
+            type Value = ToolUvExtraBuildDependencies;
+
+            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+                formatter.write_str("a map with unique keys")
+            }
+
+            fn visit_map<M>(self, mut access: M) -> Result<Self::Value, M::Error>
+            where
+                M: serde::de::MapAccess<'de>,
+            {
+                let mut groups = BTreeMap::new();
+                while let Some((key, value)) = access
+                    .next_entry::<PackageName, Vec<uv_pep508::Requirement<VerbatimParsedUrl>>>()?
+                {
+                    match groups.entry(key) {
+                        std::collections::btree_map::Entry::Occupied(entry) => {
+                            return Err(serde::de::Error::custom(format!(
+                                "duplicate extra-build-dependencies for `{}`",
+                                entry.key()
+                            )));
+                        }
+                        std::collections::btree_map::Entry::Vacant(entry) => {
+                            entry.insert(value);
+                        }
+                    }
+                }
+                Ok(ToolUvExtraBuildDependencies(groups))
+            }
+        }
+
+        deserializer.deserialize_map(DependenciesVisitor)
+    }
+}
+
 #[derive(Deserialize, OptionsMetadata, Default, Debug, Clone, PartialEq, Eq)]
 #[cfg_attr(test, derive(Serialize))]
 #[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]

crates/uv-workspace/src/workspace.rs

@@ -1868,6 +1868,7 @@ mod tests {
                       "package": null,
                       "default-groups": null,
                       "dependency-groups": null,
+                      "extra-build-dependencies": null,
                       "dev-dependencies": null,
                       "override-dependencies": null,
                       "constraint-dependencies": null,
@@ -1964,6 +1965,7 @@ mod tests {
                       "package": null,
                       "default-groups": null,
                       "dependency-groups": null,
+                      "extra-build-dependencies": null,
                       "dev-dependencies": null,
                       "override-dependencies": null,
                       "constraint-dependencies": null,
@@ -2175,6 +2177,7 @@ mod tests {
                       "package": null,
                       "default-groups": null,
                       "dependency-groups": null,
+                      "extra-build-dependencies": null,
                       "dev-dependencies": null,
                       "override-dependencies": null,
                       "constraint-dependencies": null,
@@ -2283,6 +2286,7 @@ mod tests {
                       "package": null,
                       "default-groups": null,
                       "dependency-groups": null,
+                      "extra-build-dependencies": null,
                       "dev-dependencies": null,
                       "override-dependencies": null,
                       "constraint-dependencies": null,
@@ -2404,6 +2408,7 @@ mod tests {
                       "package": null,
                       "default-groups": null,
                       "dependency-groups": null,
+                      "extra-build-dependencies": null,
                       "dev-dependencies": null,
                       "override-dependencies": null,
                       "constraint-dependencies": null,
@@ -2499,6 +2504,7 @@ mod tests {
                       "package": null,
                       "default-groups": null,
                       "dependency-groups": null,
+                      "extra-build-dependencies": null,
                       "dev-dependencies": null,
                       "override-dependencies": null,
                       "constraint-dependencies": null,

crates/uv/src/commands/build_frontend.rs

@@ -38,6 +38,7 @@ use uv_requirements::RequirementsSource;
 use uv_resolver::{ExcludeNewer, FlatIndex};
 use uv_settings::PythonInstallMirrors;
 use uv_types::{AnyErrorBuild, BuildContext, BuildIsolation, BuildStack, HashStrategy};
+use uv_workspace::pyproject::ExtraBuildDependencies;
 use uv_workspace::{DiscoveryOptions, Workspace, WorkspaceCache, WorkspaceError};
 
 use crate::commands::ExitStatus;
@@ -199,6 +200,7 @@ async fn build_impl(
         config_setting,
         no_build_isolation,
         no_build_isolation_package,
+        extra_build_dependencies,
         exclude_newer,
         link_mode,
         upgrade: _,
@@ -344,6 +346,7 @@ async fn build_impl(
             build_constraints,
             *no_build_isolation,
             no_build_isolation_package,
+            extra_build_dependencies,
             *index_strategy,
             *keyring_provider,
             *exclude_newer,
@@ -421,6 +424,7 @@ async fn build_package(
     build_constraints: &[RequirementsSource],
     no_build_isolation: bool,
     no_build_isolation_package: &[PackageName],
+    extra_build_dependencies: &ExtraBuildDependencies,
     index_strategy: IndexStrategy,
     keyring_provider: KeyringProviderType,
     exclude_newer: Option<ExcludeNewer>,
@@ -568,6 +572,7 @@ async fn build_package(
         index_strategy,
         config_setting,
         build_isolation,
+        extra_build_dependencies,
         link_mode,
         build_options,
         &hasher,

crates/uv/src/commands/pip/compile.rs

@@ -44,6 +44,7 @@ use uv_torch::{TorchMode, TorchStrategy};
 use uv_types::{BuildIsolation, EmptyInstalledPackages, HashStrategy};
 use uv_warnings::warn_user;
 use uv_workspace::WorkspaceCache;
+use uv_workspace::pyproject::ExtraBuildDependencies;
 
 use crate::commands::pip::loggers::DefaultResolveLogger;
 use crate::commands::pip::{operations, resolution_environment};
@@ -92,6 +93,7 @@ pub(crate) async fn pip_compile(
     config_settings: ConfigSettings,
     no_build_isolation: bool,
     no_build_isolation_package: Vec<PackageName>,
+    extra_build_dependencies: &ExtraBuildDependencies,
     build_options: BuildOptions,
     mut python_version: Option<PythonVersion>,
     python_platform: Option<TargetTriple>,
@@ -477,6 +479,7 @@ pub(crate) async fn pip_compile(
         index_strategy,
         &config_settings,
         build_isolation,
+        extra_build_dependencies,
         link_mode,
         &build_options,
         &build_hashes,

crates/uv/src/commands/pip/install.rs

@@ -38,6 +38,7 @@ use uv_torch::{TorchMode, TorchStrategy};
 use uv_types::{BuildIsolation, HashStrategy};
 use uv_warnings::warn_user;
 use uv_workspace::WorkspaceCache;
+use uv_workspace::pyproject::ExtraBuildDependencies;
 
 use crate::commands::pip::loggers::{DefaultInstallLogger, DefaultResolveLogger, InstallLogger};
 use crate::commands::pip::operations::Modifications;
@@ -77,6 +78,7 @@ pub(crate) async fn pip_install(
     config_settings: &ConfigSettings,
     no_build_isolation: bool,
     no_build_isolation_package: Vec<PackageName>,
+    extra_build_dependencies: &ExtraBuildDependencies,
     build_options: BuildOptions,
     modifications: Modifications,
     python_version: Option<PythonVersion>,
@@ -422,6 +424,7 @@ pub(crate) async fn pip_install(
         index_strategy,
         config_settings,
         build_isolation,
+        extra_build_dependencies,
         link_mode,
         &build_options,
         &build_hasher,

crates/uv/src/commands/pip/sync.rs

@@ -32,6 +32,7 @@ use uv_torch::{TorchMode, TorchStrategy};
 use uv_types::{BuildIsolation, HashStrategy};
 use uv_warnings::warn_user;
 use uv_workspace::WorkspaceCache;
+use uv_workspace::pyproject::ExtraBuildDependencies;
 
 use crate::commands::pip::loggers::{DefaultInstallLogger, DefaultResolveLogger};
 use crate::commands::pip::operations::Modifications;
@@ -62,6 +63,7 @@ pub(crate) async fn pip_sync(
     config_settings: &ConfigSettings,
     no_build_isolation: bool,
     no_build_isolation_package: Vec<PackageName>,
+    extra_build_dependencies: &ExtraBuildDependencies,
     build_options: BuildOptions,
     python_version: Option<PythonVersion>,
     python_platform: Option<TargetTriple>,
@@ -355,6 +357,7 @@ pub(crate) async fn pip_sync(
         index_strategy,
         config_settings,
         build_isolation,
+        extra_build_dependencies,
         link_mode,
         &build_options,
         &build_hasher,

crates/uv/src/commands/project/add.rs

@@ -434,6 +434,7 @@ pub(crate) async fn add(
                 settings.resolver.index_strategy,
                 &settings.resolver.config_setting,
                 build_isolation,
+                &settings.resolver.extra_build_dependencies,
                 settings.resolver.link_mode,
                 &settings.resolver.build_options,
                 &build_hasher,

crates/uv/src/commands/project/lock.rs

@@ -426,6 +426,7 @@ async fn do_lock(
         config_setting,
         no_build_isolation,
         no_build_isolation_package,
+        extra_build_dependencies,
         exclude_newer,
         link_mode,
         upgrade,
@@ -665,6 +666,7 @@ async fn do_lock(
         *index_strategy,
         config_setting,
         build_isolation,
+        extra_build_dependencies,
         *link_mode,
         build_options,
         &build_hasher,

crates/uv/src/commands/project/mod.rs

@@ -1646,6 +1646,7 @@ pub(crate) async fn resolve_names(
                 link_mode,
                 no_build_isolation,
                 no_build_isolation_package,
+                extra_build_dependencies,
                 prerelease: _,
                 resolution: _,
                 sources,
@@ -1704,6 +1705,7 @@ pub(crate) async fn resolve_names(
         *index_strategy,
         config_setting,
         build_isolation,
+        extra_build_dependencies,
         *link_mode,
         build_options,
         &build_hasher,
@@ -1795,6 +1797,7 @@ pub(crate) async fn resolve_environment(
         config_setting,
         no_build_isolation,
         no_build_isolation_package,
+        extra_build_dependencies,
         exclude_newer,
         link_mode,
         upgrade: _,
@@ -1909,6 +1912,7 @@ pub(crate) async fn resolve_environment(
         *index_strategy,
         config_setting,
         build_isolation,
+        extra_build_dependencies,
         *link_mode,
         build_options,
         &build_hasher,
@@ -1975,6 +1979,7 @@ pub(crate) async fn sync_environment(
         config_setting,
         no_build_isolation,
         no_build_isolation_package,
+        extra_build_dependencies,
         exclude_newer,
         link_mode,
         compile_bytecode,
@@ -2044,6 +2049,7 @@ pub(crate) async fn sync_environment(
         index_strategy,
         config_setting,
         build_isolation,
+        extra_build_dependencies,
         link_mode,
         build_options,
         &build_hasher,
@@ -2137,6 +2143,7 @@ pub(crate) async fn update_environment(
                 link_mode,
                 no_build_isolation,
                 no_build_isolation_package,
+                extra_build_dependencies,
                 prerelease,
                 resolution,
                 sources,
@@ -2264,6 +2271,7 @@ pub(crate) async fn update_environment(
         *index_strategy,
         config_setting,
         build_isolation,
+        extra_build_dependencies,
         *link_mode,
         build_options,
         &build_hasher,

crates/uv/src/commands/project/sync.rs

@@ -610,6 +610,7 @@ pub(super) async fn do_sync(
         config_setting,
         no_build_isolation,
         no_build_isolation_package,
+        extra_build_dependencies,
         exclude_newer,
         link_mode,
         compile_bytecode,
@@ -744,6 +745,7 @@ pub(super) async fn do_sync(
         index_strategy,
         config_setting,
         build_isolation,
+        extra_build_dependencies,
         link_mode,
         build_options,
         &build_hasher,

crates/uv/src/commands/project/tree.rs

@@ -202,6 +202,7 @@ pub(crate) async fn tree(
                 config_setting: _,
                 no_build_isolation: _,
                 no_build_isolation_package: _,
+                extra_build_dependencies: _,
                 exclude_newer: _,
                 link_mode: _,
                 upgrade: _,

crates/uv/src/commands/venv.rs

@@ -30,6 +30,7 @@ use uv_settings::PythonInstallMirrors;
 use uv_shell::{Shell, shlex_posix, shlex_windows};
 use uv_types::{AnyErrorBuild, BuildContext, BuildIsolation, BuildStack, HashStrategy};
 use uv_warnings::warn_user;
+use uv_workspace::pyproject::ExtraBuildDependencies;
 use uv_workspace::{DiscoveryOptions, VirtualProject, WorkspaceCache, WorkspaceError};
 
 use crate::commands::ExitStatus;
@@ -343,7 +344,7 @@ async fn venv_impl(
 
         // Do not allow builds
         let build_options = BuildOptions::new(NoBinary::None, NoBuild::All);
-
+        let extra_build_dependencies = ExtraBuildDependencies::default();
         // Prep the build context.
         let build_dispatch = BuildDispatch::new(
             &client,
@@ -357,6 +358,7 @@ async fn venv_impl(
             index_strategy,
             &config_settings,
             BuildIsolation::Isolated,
+            &extra_build_dependencies,
             link_mode,
             &build_options,
             &build_hasher,

crates/uv/src/lib.rs

@@ -520,6 +520,7 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
                 args.settings.config_setting,
                 args.settings.no_build_isolation,
                 args.settings.no_build_isolation_package,
+                &args.settings.extra_build_dependencies,
                 args.settings.build_options,
                 args.settings.python_version,
                 args.settings.python_platform,
@@ -590,6 +591,7 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
                 &args.settings.config_setting,
                 args.settings.no_build_isolation,
                 args.settings.no_build_isolation_package,
+                &args.settings.extra_build_dependencies,
                 args.settings.build_options,
                 args.settings.python_version,
                 args.settings.python_platform,
@@ -741,6 +743,7 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
                 &args.settings.config_setting,
                 args.settings.no_build_isolation,
                 args.settings.no_build_isolation_package,
+                &args.settings.extra_build_dependencies,
                 args.settings.build_options,
                 args.modifications,
                 args.settings.python_version,

crates/uv/src/settings.rs

@@ -44,7 +44,7 @@ use uv_settings::{
 use uv_static::EnvVars;
 use uv_torch::TorchMode;
 use uv_warnings::warn_user_once;
-use uv_workspace::pyproject::DependencyType;
+use uv_workspace::pyproject::{DependencyType, ExtraBuildDependencies};
 use uv_workspace::pyproject_mut::AddBoundsKind;
 
 use crate::commands::ToolRunCommand;
@@ -2664,6 +2664,7 @@ pub(crate) struct InstallerSettingsRef<'a> {
     pub(crate) config_setting: &'a ConfigSettings,
     pub(crate) no_build_isolation: bool,
     pub(crate) no_build_isolation_package: &'a [PackageName],
+    pub(crate) extra_build_dependencies: &'a ExtraBuildDependencies,
     pub(crate) exclude_newer: Option<ExcludeNewer>,
     pub(crate) link_mode: LinkMode,
     pub(crate) compile_bytecode: bool,
@@ -2689,6 +2690,7 @@ pub(crate) struct ResolverSettings {
     pub(crate) link_mode: LinkMode,
     pub(crate) no_build_isolation: bool,
     pub(crate) no_build_isolation_package: Vec<PackageName>,
+    pub(crate) extra_build_dependencies: ExtraBuildDependencies,
     pub(crate) prerelease: PrereleaseMode,
     pub(crate) resolution: ResolutionMode,
     pub(crate) sources: SourceStrategy,
@@ -2740,6 +2742,7 @@ impl From<ResolverOptions> for ResolverSettings {
             config_setting: value.config_settings.unwrap_or_default(),
             no_build_isolation: value.no_build_isolation.unwrap_or_default(),
             no_build_isolation_package: value.no_build_isolation_package.unwrap_or_default(),
+            extra_build_dependencies: value.extra_build_dependencies.unwrap_or_default(),
             exclude_newer: value.exclude_newer,
             link_mode: value.link_mode.unwrap_or_default(),
             sources: SourceStrategy::from_args(value.no_sources.unwrap_or_default()),
@@ -2828,6 +2831,7 @@ impl From<ResolverInstallerOptions> for ResolverInstallerSettings {
                 link_mode: value.link_mode.unwrap_or_default(),
                 no_build_isolation: value.no_build_isolation.unwrap_or_default(),
                 no_build_isolation_package: value.no_build_isolation_package.unwrap_or_default(),
+                extra_build_dependencies: value.extra_build_dependencies.unwrap_or_default(),
                 prerelease: value.prerelease.unwrap_or_default(),
                 resolution: value.resolution.unwrap_or_default(),
                 sources: SourceStrategy::from_args(value.no_sources.unwrap_or_default()),
@@ -2870,6 +2874,7 @@ pub(crate) struct PipSettings {
     pub(crate) torch_backend: Option<TorchMode>,
     pub(crate) no_build_isolation: bool,
     pub(crate) no_build_isolation_package: Vec<PackageName>,
+    pub(crate) extra_build_dependencies: ExtraBuildDependencies,
     pub(crate) build_options: BuildOptions,
     pub(crate) allow_empty_requirements: bool,
     pub(crate) strict: bool,
@@ -2936,6 +2941,7 @@ impl PipSettings {
             only_binary,
             no_build_isolation,
             no_build_isolation_package,
+            extra_build_dependencies,
             strict,
             extra,
             all_extras,
@@ -2992,6 +2998,7 @@ impl PipSettings {
             config_settings: top_level_config_settings,
             no_build_isolation: top_level_no_build_isolation,
             no_build_isolation_package: top_level_no_build_isolation_package,
+            extra_build_dependencies: top_level_extra_build_dependencies,
             exclude_newer: top_level_exclude_newer,
             link_mode: top_level_link_mode,
             compile_bytecode: top_level_compile_bytecode,
@@ -3025,6 +3032,8 @@ impl PipSettings {
         let no_build_isolation = no_build_isolation.combine(top_level_no_build_isolation);
         let no_build_isolation_package =
             no_build_isolation_package.combine(top_level_no_build_isolation_package);
+        let extra_build_dependencies =
+            extra_build_dependencies.combine(top_level_extra_build_dependencies);
         let exclude_newer = exclude_newer.combine(top_level_exclude_newer);
         let link_mode = link_mode.combine(top_level_link_mode);
         let compile_bytecode = compile_bytecode.combine(top_level_compile_bytecode);
@@ -3120,6 +3129,10 @@ impl PipSettings {
                 .no_build_isolation_package
                 .combine(no_build_isolation_package)
                 .unwrap_or_default(),
+            extra_build_dependencies: args
+                .extra_build_dependencies
+                .combine(extra_build_dependencies)
+                .unwrap_or_default(),
             config_setting: args
                 .config_settings
                 .combine(config_settings)
@@ -3219,6 +3232,7 @@ impl<'a> From<&'a ResolverInstallerSettings> for InstallerSettingsRef<'a> {
             config_setting: &settings.resolver.config_setting,
             no_build_isolation: settings.resolver.no_build_isolation,
             no_build_isolation_package: &settings.resolver.no_build_isolation_package,
+            extra_build_dependencies: &settings.resolver.extra_build_dependencies,
             exclude_newer: settings.resolver.exclude_newer,
             link_mode: settings.resolver.link_mode,
             compile_bytecode: settings.compile_bytecode,

crates/uv/tests/it/show_settings.rs

@@ -179,6 +179,7 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -360,6 +361,7 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -542,6 +544,7 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -756,6 +759,7 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -906,6 +910,7 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -1099,6 +1104,7 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -1339,6 +1345,7 @@ fn resolve_index_url() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -1588,6 +1595,7 @@ fn resolve_index_url() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -1794,6 +1802,7 @@ fn resolve_find_links() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -1966,6 +1975,7 @@ fn resolve_top_level() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -2196,6 +2206,7 @@ fn resolve_top_level() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -2409,6 +2420,7 @@ fn resolve_top_level() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -2580,6 +2592,7 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -2735,6 +2748,7 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -2890,6 +2904,7 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -3047,6 +3062,7 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -3195,6 +3211,7 @@ fn resolve_tool() -> anyhow::Result<()> {
             config_settings: None,
             no_build_isolation: None,
             no_build_isolation_package: None,
+            extra_build_dependencies: None,
             exclude_newer: None,
             link_mode: Some(
                 Clone,
@@ -3234,6 +3251,7 @@ fn resolve_tool() -> anyhow::Result<()> {
                 link_mode: Clone,
                 no_build_isolation: false,
                 no_build_isolation_package: [],
+                extra_build_dependencies: {},
                 prerelease: IfNecessaryOrExplicit,
                 resolution: LowestDirect,
                 sources: Enabled,
@@ -3388,6 +3406,7 @@ fn resolve_poetry_toml() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -3604,6 +3623,7 @@ fn resolve_both() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -3910,6 +3930,7 @@ fn resolve_config_file() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -3987,7 +4008,7 @@ fn resolve_config_file() -> anyhow::Result<()> {
       |
     1 | [project]
       |  ^^^^^^^
-    unknown field `project`, expected one of `required-version`, `native-tls`, `offline`, `no-cache`, `cache-dir`, `preview`, `python-preference`, `python-downloads`, `concurrent-downloads`, `concurrent-builds`, `concurrent-installs`, `index`, `index-url`, `extra-index-url`, `no-index`, `find-links`, `index-strategy`, `keyring-provider`, `allow-insecure-host`, `resolution`, `prerelease`, `fork-strategy`, `dependency-metadata`, `config-settings`, `no-build-isolation`, `no-build-isolation-package`, `exclude-newer`, `link-mode`, `compile-bytecode`, `no-sources`, `upgrade`, `upgrade-package`, `reinstall`, `reinstall-package`, `no-build`, `no-build-package`, `no-binary`, `no-binary-package`, `python-install-mirror`, `pypy-install-mirror`, `python-downloads-json-url`, `publish-url`, `trusted-publishing`, `check-url`, `add-bounds`, `pip`, `cache-keys`, `override-dependencies`, `constraint-dependencies`, `build-constraint-dependencies`, `environments`, `required-environments`, `conflicts`, `workspace`, `sources`, `managed`, `package`, `default-groups`, `dependency-groups`, `dev-dependencies`, `build-backend`
+    unknown field `project`, expected one of `required-version`, `native-tls`, `offline`, `no-cache`, `cache-dir`, `preview`, `python-preference`, `python-downloads`, `concurrent-downloads`, `concurrent-builds`, `concurrent-installs`, `index`, `index-url`, `extra-index-url`, `no-index`, `find-links`, `index-strategy`, `keyring-provider`, `allow-insecure-host`, `resolution`, `prerelease`, `fork-strategy`, `dependency-metadata`, `config-settings`, `no-build-isolation`, `no-build-isolation-package`, `extra-build-dependencies`, `exclude-newer`, `link-mode`, `compile-bytecode`, `no-sources`, `upgrade`, `upgrade-package`, `reinstall`, `reinstall-package`, `no-build`, `no-build-package`, `no-binary`, `no-binary-package`, `python-install-mirror`, `pypy-install-mirror`, `python-downloads-json-url`, `publish-url`, `trusted-publishing`, `check-url`, `add-bounds`, `pip`, `cache-keys`, `override-dependencies`, `constraint-dependencies`, `build-constraint-dependencies`, `environments`, `required-environments`, `conflicts`, `workspace`, `sources`, `managed`, `package`, `default-groups`, `dependency-groups`, `dev-dependencies`, `build-backend`
     "
     );
 
@@ -4159,6 +4180,7 @@ fn resolve_skip_empty() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -4317,6 +4339,7 @@ fn resolve_skip_empty() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -4494,6 +4517,7 @@ fn allow_insecure_host() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -4730,6 +4754,7 @@ fn index_priority() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -4945,6 +4970,7 @@ fn index_priority() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -5166,6 +5192,7 @@ fn index_priority() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -5382,6 +5409,7 @@ fn index_priority() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -5605,6 +5633,7 @@ fn index_priority() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -5821,6 +5850,7 @@ fn index_priority() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -5983,6 +6013,7 @@ fn verify_hashes() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -6131,6 +6162,7 @@ fn verify_hashes() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -6277,6 +6309,7 @@ fn verify_hashes() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -6425,6 +6458,7 @@ fn verify_hashes() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -6571,6 +6605,7 @@ fn verify_hashes() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,
@@ -6718,6 +6753,7 @@ fn verify_hashes() -> anyhow::Result<()> {
             torch_backend: None,
             no_build_isolation: false,
             no_build_isolation_package: [],
+            extra_build_dependencies: {},
             build_options: BuildOptions {
                 no_binary: None,
                 no_build: None,

crates/uv/tests/it/sync.rs

@@ -1295,6 +1295,106 @@ fn sync_build_isolation_extra() -> Result<()> {
     Ok(())
 }
 
+/// Use dedicated extra groups to install dependencies for `--no-build-isolation-package`.
+#[test]
+fn sync_build_isolation_fail() -> Result<()> {
+    let context = TestContext::new("3.12").with_filtered_counts();
+
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "myproject"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["fasttext==0.9.2"]
+
+        [build-system]
+        requires = ["setuptools >= 40.9.0"]
+        build-backend = "setuptools.build_meta"
+        "#,
+    )?;
+    let filters = std::iter::once((r"exit code: 1", "exit status: 1"))
+        .chain(context.filters())
+        .collect::<Vec<_>>();
+
+    // Running `uv sync` should fail due to missing build-dependencies
+    uv_snapshot!(&filters, context.sync(), @r#"
+    success: false
+    exit_code: 1
+    ----- stdout -----
+
+    ----- stderr -----
+      × Failed to build `fasttext==0.9.2`
+      ├─▶ The build backend returned an error
+      ╰─▶ Call to `setuptools.build_meta:__legacy__.build_wheel` failed (exit status: 1)
+
+          [stderr]
+          [CACHE_DIR]/builds-v0/[TMP]/python: No module named pip
+          Traceback (most recent call last):
+            File "<string>", line 38, in __init__
+          ModuleNotFoundError: No module named 'pybind11'
+
+          During handling of the above exception, another exception occurred:
+
+          Traceback (most recent call last):
+            File "<string>", line 14, in <module>
+            File "[CACHE_DIR]/builds-v0/[TMP]/build_meta.py", line 325, in get_requires_for_build_wheel
+              return self._get_build_requires(config_settings, requirements=['wheel'])
+                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+            File "[CACHE_DIR]/builds-v0/[TMP]/build_meta.py", line 295, in _get_build_requires
+              self.run_setup()
+            File "[CACHE_DIR]/builds-v0/[TMP]/build_meta.py", line 487, in run_setup
+              super().run_setup(setup_script=setup_script)
+            File "[CACHE_DIR]/builds-v0/[TMP]/build_meta.py", line 311, in run_setup
+              exec(code, locals())
+            File "<string>", line 72, in <module>
+            File "<string>", line 41, in __init__
+          RuntimeError: pybind11 install failed.
+
+          hint: This usually indicates a problem with the package or the build environment.
+      help: `fasttext` (v0.9.2) was included because `myproject` (v0.1.0) depends on `fasttext==0.9.2`
+    "#);
+
+    // Adding extra-build-dependencies should solve the issue
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "myproject"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["fasttext==0.9.2"]
+
+        [build-system]
+        requires = ["setuptools >= 40.9.0"]
+        build-backend = "setuptools.build_meta"
+        
+        [tool.uv.extra-build-dependencies]
+        fasttext = ["setuptools", "wheel", "pybind11"]
+        "#,
+    )?;
+
+    uv_snapshot!(&filters, context.sync(), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved [N] packages in [TIME]
+    Prepared [N] packages in [TIME]
+    Installed [N] packages in [TIME]
+     + fasttext==0.9.2
+     + myproject==0.1.0 (from file://[TEMP_DIR]/)
+     + numpy==1.26.4
+     + pybind11==2.11.1
+     + setuptools==69.2.0
+    ");
+
+    assert!(context.temp_dir.child("uv.lock").exists());
+
+    Ok(())
+}
+
 /// Avoid using incompatible versions for build dependencies that are also part of the resolved
 /// environment. This is a very subtle issue, but: when locking, we don't enforce platform
 /// compatibility. So, if we reuse the resolver state to install, and the install itself has to

docs/reference/settings.md

@@ -202,6 +202,28 @@ environments = ["sys_platform == 'darwin'"]
 
 ---
 
+### [`extra-build-dependencies`](#extra-build-dependencies) {: #extra-build-dependencies }
+
+Additional build dependencies for dependencies.
+
+This is intended for enabling more packages to be built with
+build-isolation, by adding dependencies that they ambiently
+assume to exist (`setuptools` and `pip` being common).
+
+**Default value**: `[]`
+
+**Type**: `dict`
+
+**Example usage**:
+
+```toml title="pyproject.toml"
+
+[tool.uv.extra-build-dependencies]
+pytest = ["pip"]
+```
+
+---
+
 ### [`index`](#index) {: #index }
 
 The indexes to use when resolving dependencies.
@@ -1070,6 +1092,36 @@ behave consistently across timezones.
 
 ---
 
+### [`extra-build-dependencies`](#extra-build-dependencies) {: #extra-build-dependencies }
+
+Additional build dependencies for dependencies.
+
+This is intended for enabling more packages to be built with
+build-isolation, by adding dependencies that they ambiently
+assume to exist (`setuptools` and `pip` being common).
+
+**Default value**: `[]`
+
+**Type**: `dict`
+
+**Example usage**:
+
+=== "pyproject.toml"
+
+    ```toml
+    [tool.uv]
+    [extra-build-dependencies] 
+    pytest = ["setuptools"]
+    ```
+=== "uv.toml"
+
+    ```toml
+    [extra-build-dependencies] 
+    pytest = ["setuptools"]
+    ```
+
+---
+
 ### [`extra-index-url`](#extra-index-url) {: #extra-index-url }
 
 Extra URLs of package indexes to use, in addition to `--index-url`.
@@ -2504,6 +2556,38 @@ Only applies to `pyproject.toml`, `setup.py`, and `setup.cfg` sources.
 
 ---
 
+#### [`extra-build-dependencies`](#pip_extra-build-dependencies) {: #pip_extra-build-dependencies }
+<span id="extra-build-dependencies"></span>
+
+Additional build dependencies for dependencies.
+
+This is intended for enabling more packages to be built with
+build-isolation, by adding dependencies that they ambiently
+assume to exist (`setuptools` and `pip` being common).
+
+**Default value**: `[]`
+
+**Type**: `dict`
+
+**Example usage**:
+
+=== "pyproject.toml"
+
+    ```toml
+    [tool.uv.pip]
+    [extra-build-dependencies]
+    pytest = ["setuptools"]
+    ```
+=== "uv.toml"
+
+    ```toml
+    [pip]
+    [extra-build-dependencies]
+    pytest = ["setuptools"]
+    ```
+
+---
+
 #### [`extra-index-url`](#pip_extra-index-url) {: #pip_extra-index-url }
 <span id="extra-index-url"></span>
 

uv.schema.json

@@ -203,6 +203,17 @@
         }
       ]
     },
+    "extra-build-dependencies": {
+      "description": "Additional build dependencies for dependencies.\n\nThis is intended for enabling more packages to be built with build-isolation, by adding dependencies that they ambiently assume to exist (`setuptools` and `pip` being common).",
+      "anyOf": [
+        {
+          "$ref": "#/definitions/ToolUvExtraBuildDependencies"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
     "extra-index-url": {
       "description": "Extra URLs of package indexes to use, in addition to `--index-url`.\n\nAccepts either a repository compliant with [PEP 503](https://peps.python.org/pep-0503/)\n(the simple repository API), or a local directory laid out in the same format.\n\nAll indexes provided via this flag take priority over the index specified by\n[`index_url`](#index-url) or [`index`](#index) with `default = true`. When multiple indexes\nare provided, earlier values take priority.\n\nTo control uv's resolution strategy when multiple indexes are present, see\n[`index_strategy`](#index-strategy).\n\n(Deprecated: use `index` instead.)",
       "type": [
@@ -1206,6 +1217,19 @@
             "$ref": "#/definitions/ExtraName"
           }
         },
+        "extra-build-dependencies": {
+          "description": "Additional build dependencies for dependencies.\n\nThis is intended for enabling more packages to be built with build-isolation, by adding dependencies that they ambiently assume to exist (`setuptools` and `pip` being common).",
+          "type": [
+            "object",
+            "null"
+          ],
+          "additionalProperties": {
+            "type": "array",
+            "items": {
+              "$ref": "#/definitions/Requirement"
+            }
+          }
+        },
         "extra-index-url": {
           "description": "Extra URLs of package indexes to use, in addition to `--index-url`.\n\nAccepts either a repository compliant with [PEP 503](https://peps.python.org/pep-0503/)\n(the simple repository API), or a local directory laid out in the same format.\n\nAll indexes provided via this flag take priority over the index specified by\n[`index_url`](#index-url). When multiple indexes are provided, earlier values take priority.\n\nTo control uv's resolution strategy when multiple indexes are present, see\n[`index_strategy`](#index-strategy).",
           "type": [
@@ -2234,6 +2258,15 @@
         "$ref": "#/definitions/DependencyGroupSettings"
       }
     },
+    "ToolUvExtraBuildDependencies": {
+      "type": "object",
+      "additionalProperties": {
+        "type": "array",
+        "items": {
+          "$ref": "#/definitions/Requirement"
+        }
+      }
+    },
     "ToolUvSources": {
       "type": "object",
       "additionalProperties": {