Use union of requires-python in workspace

crates/pep440-rs/src/version_specifier.rs

@@ -1,5 +1,6 @@
 #[cfg(feature = "pyo3")]
 use std::hash::{Hash, Hasher};
+use std::ops::Bound;
 use std::{cmp::Ordering, str::FromStr};
 
 #[cfg(feature = "pyo3")]
@@ -415,6 +416,50 @@ impl VersionSpecifier {
         self.version.any_prerelease()
     }
 
+    /// Returns the version specifiers whose union represents the given range.
+    pub fn from_bounds(
+        bounds: (&Bound<Version>, &Bound<Version>),
+    ) -> impl Iterator<Item = VersionSpecifier> {
+        let (b1, b2) = match bounds {
+            (Bound::Included(v1), Bound::Included(v2)) if v1 == v2 => {
+                (Some(VersionSpecifier::equals_version(v1.clone())), None)
+            }
+            (lower, upper) => (
+                VersionSpecifier::from_lower_bound(lower),
+                VersionSpecifier::from_upper_bound(upper),
+            ),
+        };
+
+        b1.into_iter().chain(b2)
+    }
+
+    /// Returns a version specifier representing the given lower bound.
+    fn from_lower_bound(bound: &Bound<Version>) -> Option<VersionSpecifier> {
+        match bound {
+            Bound::Included(version) => Some(
+                VersionSpecifier::from_version(Operator::GreaterThanEqual, version.clone())
+                    .unwrap(),
+            ),
+            Bound::Excluded(version) => Some(
+                VersionSpecifier::from_version(Operator::GreaterThan, version.clone()).unwrap(),
+            ),
+            Bound::Unbounded => None,
+        }
+    }
+
+    /// Returns a version specifier representing the given upper bound.
+    fn from_upper_bound(bound: &Bound<Version>) -> Option<VersionSpecifier> {
+        match bound {
+            Bound::Included(version) => Some(
+                VersionSpecifier::from_version(Operator::LessThanEqual, version.clone()).unwrap(),
+            ),
+            Bound::Excluded(version) => {
+                Some(VersionSpecifier::from_version(Operator::LessThan, version.clone()).unwrap())
+            }
+            Bound::Unbounded => None,
+        }
+    }
+
     /// Whether the given version satisfies the version range
     ///
     /// e.g. `>=1.19,<2.0` and `1.21` -> true

crates/uv-resolver/src/error.rs

@@ -2,20 +2,22 @@ use std::collections::{BTreeMap, BTreeSet};
 use std::fmt::Formatter;
 use std::sync::Arc;
 
+use dashmap::DashMap;
 use indexmap::IndexMap;
 use pubgrub::range::Range;
 use pubgrub::report::{DefaultStringReporter, DerivationTree, External, Reporter};
 use rustc_hash::{FxHashMap, FxHashSet};
 
-use dashmap::DashMap;
 use distribution_types::{BuiltDist, IndexLocations, InstalledDist, SourceDist};
 use pep440_rs::Version;
 use pep508_rs::Requirement;
 use uv_normalize::PackageName;
 
 use crate::candidate_selector::CandidateSelector;
 use crate::dependency_provider::UvDependencyProvider;
-use crate::pubgrub::{PubGrubPackage, PubGrubPackageInner, PubGrubReportFormatter};
+use crate::pubgrub::{
+    PubGrubPackage, PubGrubPackageInner, PubGrubReportFormatter, PubGrubSpecifierError,
+};
 use crate::python_requirement::PythonRequirement;
 use crate::resolver::{
     FxOnceMap, IncompletePackage, UnavailablePackage, UnavailableReason, VersionsResponse,
@@ -44,8 +46,8 @@ pub enum ResolveError {
         metadata: PackageName,
     },
 
-    #[error("~= operator requires at least two release segments: `{0}`")]
-    InvalidTildeEquals(pep440_rs::VersionSpecifier),
+    #[error(transparent)]
+    PubGrubSpecifier(#[from] PubGrubSpecifierError),
 
     #[error("Requirements contain conflicting URLs for package `{0}`:\n- {1}\n- {2}")]
     ConflictingUrlsDirect(PackageName, String, String),

crates/uv-resolver/src/lib.rs

@@ -8,6 +8,7 @@ pub use manifest::Manifest;
 pub use options::{Options, OptionsBuilder};
 pub use preferences::{Preference, PreferenceError};
 pub use prerelease_mode::PreReleaseMode;
+pub use pubgrub::{PubGrubSpecifier, PubGrubSpecifierError};
 pub use python_requirement::PythonRequirement;
 pub use resolution::{AnnotationStyle, DisplayResolutionGraph, ResolutionGraph};
 pub use resolution_mode::ResolutionMode;

crates/uv-resolver/src/pubgrub/dependencies.rs

@@ -237,7 +237,7 @@ impl PubGrubRequirement {
                         .map(|specifier| {
                             Locals::map(expected, specifier)
                                 .map_err(ResolveError::InvalidVersion)
-                                .and_then(|specifier| PubGrubSpecifier::try_from(&specifier))
+                                .and_then(|specifier| Ok(PubGrubSpecifier::try_from(&specifier)?))
                         })
                         .fold_ok(Range::full(), |range, specifier| {
                             range.intersection(&specifier.into())

crates/uv-resolver/src/pubgrub/mod.rs

@@ -3,7 +3,7 @@ pub(crate) use crate::pubgrub::distribution::PubGrubDistribution;
 pub(crate) use crate::pubgrub::package::{PubGrubPackage, PubGrubPackageInner, PubGrubPython};
 pub(crate) use crate::pubgrub::priority::{PubGrubPriorities, PubGrubPriority};
 pub(crate) use crate::pubgrub::report::PubGrubReportFormatter;
-pub(crate) use crate::pubgrub::specifier::PubGrubSpecifier;
+pub use crate::pubgrub::specifier::{PubGrubSpecifier, PubGrubSpecifierError};
 
 mod dependencies;
 mod distribution;

crates/uv-resolver/src/pubgrub/specifier.rs

@@ -1,13 +1,18 @@
 use itertools::Itertools;
 use pubgrub::range::Range;
+use thiserror::Error;
 
 use pep440_rs::{Operator, PreRelease, Version, VersionSpecifier, VersionSpecifiers};
 
-use crate::ResolveError;
+#[derive(Debug, Error)]
+pub enum PubGrubSpecifierError {
+    #[error("~= operator requires at least two release segments: `{0}`")]
+    InvalidTildeEquals(VersionSpecifier),
+}
 
 /// A range of versions that can be used to satisfy a requirement.
 #[derive(Debug)]
-pub(crate) struct PubGrubSpecifier(Range<Version>);
+pub struct PubGrubSpecifier(Range<Version>);
 
 impl PubGrubSpecifier {
     /// Returns `true` if the [`PubGrubSpecifier`] is a subset of the other.
@@ -24,10 +29,10 @@ impl From<PubGrubSpecifier> for Range<Version> {
 }
 
 impl TryFrom<&VersionSpecifiers> for PubGrubSpecifier {
-    type Error = ResolveError;
+    type Error = PubGrubSpecifierError;
 
     /// Convert a PEP 440 specifier to a PubGrub-compatible version range.
-    fn try_from(specifiers: &VersionSpecifiers) -> Result<Self, ResolveError> {
+    fn try_from(specifiers: &VersionSpecifiers) -> Result<Self, PubGrubSpecifierError> {
         let range = specifiers
             .iter()
             .map(crate::pubgrub::PubGrubSpecifier::try_from)
@@ -39,10 +44,10 @@ impl TryFrom<&VersionSpecifiers> for PubGrubSpecifier {
 }
 
 impl TryFrom<&VersionSpecifier> for PubGrubSpecifier {
-    type Error = ResolveError;
+    type Error = PubGrubSpecifierError;
 
     /// Convert a PEP 440 specifier to a PubGrub-compatible version range.
-    fn try_from(specifier: &VersionSpecifier) -> Result<Self, ResolveError> {
+    fn try_from(specifier: &VersionSpecifier) -> Result<Self, PubGrubSpecifierError> {
         let ranges = match specifier.operator() {
             Operator::Equal => {
                 let version = specifier.version().clone();
@@ -58,7 +63,7 @@ impl TryFrom<&VersionSpecifier> for PubGrubSpecifier {
             }
             Operator::TildeEqual => {
                 let [rest @ .., last, _] = specifier.version().release() else {
-                    return Err(ResolveError::InvalidTildeEquals(specifier.clone()));
+                    return Err(PubGrubSpecifierError::InvalidTildeEquals(specifier.clone()));
                 };
                 let upper = Version::new(rest.iter().chain([&(last + 1)]))
                     .with_epoch(specifier.version().epoch())

crates/uv/Cargo.toml

@@ -50,6 +50,7 @@ indicatif = { workspace = true }
 itertools = { workspace = true }
 miette = { workspace = true, features = ["fancy"] }
 owo-colors = { workspace = true }
+pubgrub = { workspace = true }
 rayon = { workspace = true }
 regex = { workspace = true }
 rustc-hash = { workspace = true }

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

@@ -738,4 +738,7 @@ pub(crate) enum Error {
 
     #[error(transparent)]
     Anyhow(#[from] anyhow::Error),
+
+    #[error(transparent)]
+    PubGrubSpecifier(#[from] uv_resolver::PubGrubSpecifierError),
 }

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

@@ -1,10 +1,11 @@
 use anstream::eprint;
 use anyhow::Result;
-use std::borrow::Cow;
+use itertools::Itertools;
+use pubgrub::range::Range;
 
 use distribution_types::{IndexLocations, UnresolvedRequirementSpecification};
 use install_wheel_rs::linker::LinkMode;
-use pep440_rs::{VersionSpecifier, VersionSpecifiers};
+use pep440_rs::{Version, VersionSpecifier, VersionSpecifiers};
 use uv_cache::Cache;
 use uv_client::RegistryClientBuilder;
 use uv_configuration::{
@@ -17,7 +18,7 @@ use uv_git::GitResolver;
 use uv_interpreter::PythonEnvironment;
 use uv_normalize::PackageName;
 use uv_requirements::upgrade::{read_lockfile, LockedRequirements};
-use uv_resolver::{ExcludeNewer, FlatIndex, InMemoryIndex, Lock, OptionsBuilder};
+use uv_resolver::{ExcludeNewer, FlatIndex, InMemoryIndex, Lock, OptionsBuilder, PubGrubSpecifier};
 use uv_types::{BuildIsolation, EmptyInstalledPackages, HashStrategy, InFlight};
 use uv_warnings::warn_user;
 
@@ -106,13 +107,36 @@ pub(super) async fn do_lock(
 
     // Determine the supported Python range. If no range is defined, and warn and default to the
     // current minor version.
-    let project = root_project_name
-        .as_ref()
-        .and_then(|name| workspace.packages().get(name));
-    let requires_python = if let Some(requires_python) =
-        project.and_then(|root_project| root_project.project().requires_python.as_ref())
-    {
-        Cow::Borrowed(requires_python)
+    //
+    // For a workspace, we compute the union of all workspace requires-python values, ensuring we
+    // keep track of `None` vs. a full range.
+    let requires_python_workspace = workspace
+        .packages()
+        .values()
+        .filter_map(|member| {
+            member
+                .pyproject_toml()
+                .project
+                .as_ref()
+                .and_then(|project| project.requires_python.as_ref())
+        })
+        // Convert to pubgrub range, perform the union, convert back to pep440_rs.
+        .map(PubGrubSpecifier::try_from)
+        .fold_ok(None, |range: Option<Range<Version>>, requires_python| {
+            if let Some(range) = range {
+                Some(range.union(&requires_python.into()))
+            } else {
+                Some(requires_python.into())
+            }
+        })?
+        .map(|range| {
+            range
+                .iter()
+                .flat_map(VersionSpecifier::from_bounds)
+                .collect()
+        });
+    let requires_python = if let Some(requires_python) = requires_python_workspace {
+        requires_python
     } else {
         let requires_python = VersionSpecifiers::from(
             VersionSpecifier::greater_than_equal_version(venv.interpreter().python_minor_version()),
@@ -124,7 +148,7 @@ pub(super) async fn do_lock(
                 .map(ToString::to_string)
                 .unwrap_or("workspace".to_string()),
         );
-        Cow::Owned(requires_python)
+        requires_python
     };
 
     // Determine the tags, markers, and interpreter to use for resolution.

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

@@ -62,6 +62,9 @@ pub(crate) enum ProjectError {
 
     #[error(transparent)]
     Operation(#[from] pip::operations::Error),
+
+    #[error(transparent)]
+    PubGrubSpecifier(#[from] uv_resolver::PubGrubSpecifierError),
 }
 
 /// Initialize a virtual environment for the current project.