Add tool.uv.build-constraint-dependencies to pyproject.toml

crates/uv-scripts/src/lib.rs

@@ -331,6 +331,7 @@ pub struct ToolUv {
     pub top_level: ResolverInstallerOptions,
     pub override_dependencies: Option<Vec<uv_pep508::Requirement<VerbatimParsedUrl>>>,
     pub constraint_dependencies: Option<Vec<uv_pep508::Requirement<VerbatimParsedUrl>>>,
+    pub build_constraint_dependencies: Option<Vec<uv_pep508::Requirement<VerbatimParsedUrl>>>,
     pub sources: Option<BTreeMap<PackageName, Sources>>,
 }
 

crates/uv-settings/src/settings.rs

@@ -107,6 +107,9 @@ pub struct Options {
     #[cfg_attr(feature = "schemars", schemars(skip))]
     pub constraint_dependencies: Option<Vec<Requirement<VerbatimParsedUrl>>>,
 
+    #[cfg_attr(feature = "schemars", schemars(skip))]
+    pub build_constraint_dependencies: Option<Vec<Requirement<VerbatimParsedUrl>>>,
+
     #[cfg_attr(feature = "schemars", schemars(skip))]
     pub environments: Option<SupportedEnvironments>,
 
@@ -1792,6 +1795,7 @@ pub struct OptionsWire {
     // They're respected in both `pyproject.toml` and `uv.toml` files.
     override_dependencies: Option<Vec<Requirement<VerbatimParsedUrl>>>,
     constraint_dependencies: Option<Vec<Requirement<VerbatimParsedUrl>>>,
+    build_constraint_dependencies: Option<Vec<Requirement<VerbatimParsedUrl>>>,
     environments: Option<SupportedEnvironments>,
     required_environments: Option<SupportedEnvironments>,
 
@@ -1858,6 +1862,7 @@ impl From<OptionsWire> for Options {
             cache_keys,
             override_dependencies,
             constraint_dependencies,
+            build_constraint_dependencies,
             environments,
             required_environments,
             conflicts,
@@ -1922,6 +1927,7 @@ impl From<OptionsWire> for Options {
             cache_keys,
             override_dependencies,
             constraint_dependencies,
+            build_constraint_dependencies,
             environments,
             required_environments,
             install_mirrors: PythonInstallMirrors::resolve(

crates/uv-workspace/src/pyproject.rs

@@ -479,6 +479,37 @@ pub struct ToolUv {
     )]
     pub constraint_dependencies: Option<Vec<uv_pep508::Requirement<VerbatimParsedUrl>>>,
 
+    /// Constraints to apply when solving build dependencies.
+    ///
+    /// Build constraints are used to restrict the versions of build dependencies that are selected
+    /// when building a package during resolution or installation.
+    ///
+    /// Including a package as a constraint will _not_ trigger installation of the package during
+    /// a build; instead, the package must be requested elsewhere in the project's build dependency
+    /// graph.
+    ///
+    /// !!! note
+    ///     In `uv lock`, `uv sync`, and `uv run`, uv will only read `build-constraint-dependencies` from
+    ///     the `pyproject.toml` at the workspace root, and will ignore any declarations in other
+    ///     workspace members or `uv.toml` files.
+    #[cfg_attr(
+        feature = "schemars",
+        schemars(
+            with = "Option<Vec<String>>",
+            description = "PEP 508-style requirements, e.g., `ruff==0.5.0`, or `ruff @ https://...`."
+        )
+    )]
+    #[option(
+        default = "[]",
+        value_type = "list[str]",
+        example = r#"
+            # Ensure that the setuptools v60.0.0 is used whenever a package has a build dependency
+            # on setuptools.
+            build-constraint-dependencies = ["setuptools==60.0.0"]
+        "#
+    )]
+    pub build_constraint_dependencies: Option<Vec<uv_pep508::Requirement<VerbatimParsedUrl>>>,
+
     /// A list of supported environments against which to resolve dependencies.
     ///
     /// By default, uv will resolve for all possible environments during a `uv lock` operation.

crates/uv-workspace/src/workspace.rs

@@ -496,6 +496,20 @@ impl Workspace {
         constraints.clone()
     }
 
+    /// Returns the set of build constraints for the workspace.
+    pub fn build_constraints(&self) -> Vec<uv_pep508::Requirement<VerbatimParsedUrl>> {
+        let Some(build_constraints) = self
+            .pyproject_toml
+            .tool
+            .as_ref()
+            .and_then(|tool| tool.uv.as_ref())
+            .and_then(|uv| uv.build_constraint_dependencies.as_ref())
+        else {
+            return vec![];
+        };
+        build_constraints.clone()
+    }
+
     /// The path to the workspace root, the directory containing the top level `pyproject.toml` with
     /// the `uv.tool.workspace`, or the `pyproject.toml` in an implicit single workspace project.
     pub fn install_path(&self) -> &PathBuf {
@@ -1725,6 +1739,7 @@ mod tests {
                       "dev-dependencies": null,
                       "override-dependencies": null,
                       "constraint-dependencies": null,
+                      "build-constraint-dependencies": null,
                       "environments": null,
                       "required-environments": null,
                       "conflicts": null
@@ -1818,6 +1833,7 @@ mod tests {
                       "dev-dependencies": null,
                       "override-dependencies": null,
                       "constraint-dependencies": null,
+                      "build-constraint-dependencies": null,
                       "environments": null,
                       "required-environments": null,
                       "conflicts": null
@@ -2025,6 +2041,7 @@ mod tests {
                       "dev-dependencies": null,
                       "override-dependencies": null,
                       "constraint-dependencies": null,
+                      "build-constraint-dependencies": null,
                       "environments": null,
                       "required-environments": null,
                       "conflicts": null
@@ -2130,6 +2147,7 @@ mod tests {
                       "dev-dependencies": null,
                       "override-dependencies": null,
                       "constraint-dependencies": null,
+                      "build-constraint-dependencies": null,
                       "environments": null,
                       "required-environments": null,
                       "conflicts": null
@@ -2248,6 +2266,7 @@ mod tests {
                       "dev-dependencies": null,
                       "override-dependencies": null,
                       "constraint-dependencies": null,
+                      "build-constraint-dependencies": null,
                       "environments": null,
                       "required-environments": null,
                       "conflicts": null
@@ -2340,6 +2359,7 @@ mod tests {
                       "dev-dependencies": null,
                       "override-dependencies": null,
                       "constraint-dependencies": null,
+                      "build-constraint-dependencies": null,
                       "environments": null,
                       "required-environments": null,
                       "conflicts": null

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

@@ -56,6 +56,7 @@ pub(crate) async fn pip_compile(
     build_constraints: &[RequirementsSource],
     constraints_from_workspace: Vec<Requirement>,
     overrides_from_workspace: Vec<Requirement>,
+    build_constraints_from_workspace: Vec<Requirement>,
     environments: SupportedEnvironments,
     extras: ExtrasSpecification,
     groups: DevGroupsSpecification,
@@ -184,8 +185,17 @@ pub(crate) async fn pip_compile(
         .collect();
 
     // Read build constraints.
-    let build_constraints =
-        operations::read_constraints(build_constraints, &client_builder).await?;
+    let build_constraints: Vec<NameRequirementSpecification> =
+        operations::read_constraints(build_constraints, &client_builder)
+            .await?
+            .iter()
+            .cloned()
+            .chain(
+                build_constraints_from_workspace
+                    .into_iter()
+                    .map(NameRequirementSpecification::from),
+            )
+            .collect();
 
     // If all the metadata could be statically resolved, validate that every extra was used. If we
     // need to resolve metadata via PEP 517, we don't know which extras are used until much later.

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

@@ -51,6 +51,7 @@ pub(crate) async fn pip_install(
     build_constraints: &[RequirementsSource],
     constraints_from_workspace: Vec<Requirement>,
     overrides_from_workspace: Vec<Requirement>,
+    build_constraints_from_workspace: Vec<Requirement>,
     extras: &ExtrasSpecification,
     groups: &DevGroupsSpecification,
     resolution_mode: ResolutionMode,
@@ -123,10 +124,6 @@ pub(crate) async fn pip_install(
     )
     .await?;
 
-    // Read build constraints.
-    let build_constraints =
-        operations::read_constraints(build_constraints, &client_builder).await?;
-
     let constraints: Vec<NameRequirementSpecification> = constraints
         .iter()
         .cloned()
@@ -147,6 +144,20 @@ pub(crate) async fn pip_install(
         )
         .collect();
 
+    // Read build constraints.
+    let build_constraints: Vec<NameRequirementSpecification> =
+        operations::read_constraints(build_constraints, &client_builder)
+            .await?
+            .iter()
+            .cloned()
+            .chain(
+                build_constraints_from_workspace
+                    .iter()
+                    .cloned()
+                    .map(NameRequirementSpecification::from),
+            )
+            .collect();
+
     // Detect the current Python interpreter.
     let environment = if target.is_some() || prefix.is_some() {
         let installation = PythonInstallation::find(

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

@@ -366,13 +366,15 @@ async fn do_lock(
     let requirements = target.requirements();
     let overrides = target.overrides();
     let constraints = target.constraints();
+    let build_constraints = target.build_constraints();
     let dependency_groups = target.dependency_groups()?;
     let source_trees = vec![];
 
     // If necessary, lower the overrides and constraints.
     let requirements = target.lower(requirements, index_locations, sources)?;
     let overrides = target.lower(overrides, index_locations, sources)?;
     let constraints = target.lower(constraints, index_locations, sources)?;
+    let build_constraints = target.lower(build_constraints, index_locations, sources)?;
     let dependency_groups = dependency_groups
         .into_iter()
         .map(|(name, requirements)| {
@@ -556,9 +558,10 @@ async fn do_lock(
         .build();
     let hasher = HashStrategy::Generate(HashGeneration::Url);
 
+    let build_constraints = Constraints::from_requirements(build_constraints.iter().cloned());
+
     // TODO(charlie): These are all default values. We should consider whether we want to make them
     // optional on the downstream APIs.
-    let build_constraints = Constraints::default();
     let build_hasher = HashStrategy::default();
     let extras = ExtrasSpecification::default();
     let groups = DevGroupsSpecification::default();

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

@@ -79,6 +79,23 @@ impl<'lock> LockTarget<'lock> {
         }
     }
 
+    /// Returns the set of build constraints for the [`LockTarget`].
+    pub(crate) fn build_constraints(self) -> Vec<uv_pep508::Requirement<VerbatimParsedUrl>> {
+        match self {
+            Self::Workspace(workspace) => workspace.build_constraints(),
+            Self::Script(script) => script
+                .metadata
+                .tool
+                .as_ref()
+                .and_then(|tool| tool.uv.as_ref())
+                .and_then(|uv| uv.build_constraint_dependencies.as_ref())
+                .into_iter()
+                .flatten()
+                .cloned()
+                .collect(),
+        }
+    }
+
     /// Return the dependency groups that are attached to the target directly, as opposed to being
     /// attached to any members within the target.
     pub(crate) fn dependency_groups(

crates/uv/src/lib.rs

@@ -389,6 +389,7 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
                 &build_constraints,
                 args.constraints_from_workspace,
                 args.overrides_from_workspace,
+                args.build_constraints_from_workspace,
                 args.environments,
                 args.settings.extras,
                 args.settings.groups,
@@ -561,6 +562,7 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
                 &build_constraints,
                 args.constraints_from_workspace,
                 args.overrides_from_workspace,
+                args.build_constraints_from_workspace,
                 &args.settings.extras,
                 &args.settings.groups,
                 args.settings.resolution,

crates/uv/src/settings.rs

@@ -1540,6 +1540,7 @@ pub(crate) struct PipCompileSettings {
     pub(crate) build_constraints: Vec<PathBuf>,
     pub(crate) constraints_from_workspace: Vec<Requirement>,
     pub(crate) overrides_from_workspace: Vec<Requirement>,
+    pub(crate) build_constraints_from_workspace: Vec<Requirement>,
     pub(crate) environments: SupportedEnvironments,
     pub(crate) refresh: Refresh,
     pub(crate) settings: PipSettings,
@@ -1626,6 +1627,20 @@ impl PipCompileSettings {
             Vec::new()
         };
 
+        let build_constraints_from_workspace = if let Some(configuration) = &filesystem {
+            configuration
+                .build_constraint_dependencies
+                .clone()
+                .unwrap_or_default()
+                .into_iter()
+                .map(|requirement| {
+                    Requirement::from(requirement.with_origin(RequirementOrigin::Workspace))
+                })
+                .collect()
+        } else {
+            Vec::new()
+        };
+
         let environments = if let Some(configuration) = &filesystem {
             configuration.environments.clone().unwrap_or_default()
         } else {
@@ -1648,6 +1663,7 @@ impl PipCompileSettings {
                 .collect(),
             constraints_from_workspace,
             overrides_from_workspace,
+            build_constraints_from_workspace,
             environments,
             refresh: Refresh::from(refresh),
             settings: PipSettings::combine(
@@ -1783,6 +1799,7 @@ pub(crate) struct PipInstallSettings {
     pub(crate) dry_run: DryRun,
     pub(crate) constraints_from_workspace: Vec<Requirement>,
     pub(crate) overrides_from_workspace: Vec<Requirement>,
+    pub(crate) build_constraints_from_workspace: Vec<Requirement>,
     pub(crate) modifications: Modifications,
     pub(crate) refresh: Refresh,
     pub(crate) settings: PipSettings,
@@ -1858,6 +1875,20 @@ impl PipInstallSettings {
             Vec::new()
         };
 
+        let build_constraints_from_workspace = if let Some(configuration) = &filesystem {
+            configuration
+                .build_constraint_dependencies
+                .clone()
+                .unwrap_or_default()
+                .into_iter()
+                .map(|requirement| {
+                    Requirement::from(requirement.with_origin(RequirementOrigin::Workspace))
+                })
+                .collect()
+        } else {
+            Vec::new()
+        };
+
         Self {
             package,
             requirements,
@@ -1877,6 +1908,7 @@ impl PipInstallSettings {
             dry_run: DryRun::from_args(dry_run),
             constraints_from_workspace,
             overrides_from_workspace,
+            build_constraints_from_workspace,
             modifications: if flag(exact, inexact).unwrap_or(false) {
                 Modifications::Exact
             } else {