Ignore dynamic version in source dist

When encountering `dynamic = ["version"]` in the pyproject.toml of a source dist, we can ignore that and treat it as a statically known metadata distribution, since the filename tells us the version and that version must not change on build.

This fixed locking PyGObject 3.50.0 from `
pygobject-3.50.0.tar.gz` (minimized):

```toml
[project]
name = "PyGObject"
description = "Python bindings for GObject Introspection"
requires-python = ">=3.9, <4.0"
dependencies = [
    "pycairo>=1.16"
]
dynamic = ["version"]
```

Afterwards, `uv add --no-sync toga` passes on Ubuntu 24.04 without the pygobject build deps, when previously it needed `{ name = "pygobject", version = "3.50.0", requires-dist = [], requires-python = ">=3.9" }`.

Author: konstin

crates/uv-distribution/src/source/mod.rs

@@ -1916,7 +1916,7 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
         subdirectory: Option<&Path>,
     ) -> Result<Option<ResolutionMetadata>, Error> {
         // Attempt to read static metadata from the `pyproject.toml`.
-        match read_pyproject_toml(source_root, subdirectory).await {
+        match read_pyproject_toml(source_root, subdirectory, source.version()).await {
             Ok(metadata) => {
                 debug!("Found static `pyproject.toml` for: {source}");
 
@@ -2339,6 +2339,7 @@ async fn read_pkg_info(
 async fn read_pyproject_toml(
     source_tree: &Path,
     subdirectory: Option<&Path>,
+    sdist_version: Option<&Version>,
 ) -> Result<ResolutionMetadata, Error> {
     // Read the `pyproject.toml` file.
     let pyproject_toml = match subdirectory {
@@ -2354,8 +2355,8 @@ async fn read_pyproject_toml(
     };
 
     // Parse the metadata.
-    let metadata =
-        ResolutionMetadata::parse_pyproject_toml(&content).map_err(Error::PyprojectToml)?;
+    let metadata = ResolutionMetadata::parse_pyproject_toml(&content, sdist_version)
+        .map_err(Error::PyprojectToml)?;
 
     Ok(metadata)
 }

crates/uv-pypi-types/src/metadata/metadata_resolver.rs

@@ -151,8 +151,11 @@ impl ResolutionMetadata {
         })
     }
 
-    pub fn parse_pyproject_toml(toml: &str) -> Result<Self, MetadataError> {
-        parse_pyproject_toml(toml)
+    pub fn parse_pyproject_toml(
+        toml: &str,
+        sdist_version: Option<&Version>,
+    ) -> Result<Self, MetadataError> {
+        parse_pyproject_toml(toml, sdist_version)
     }
 }
 

crates/uv-pypi-types/src/metadata/pyproject_toml.rs

@@ -12,7 +12,13 @@ use uv_pep440::{Version, VersionSpecifiers};
 use uv_pep508::Requirement;
 
 /// Extract the metadata from a `pyproject.toml` file, as specified in PEP 621.
-pub(crate) fn parse_pyproject_toml(contents: &str) -> Result<ResolutionMetadata, MetadataError> {
+///
+/// If we're coming from a source distribution, we may already know the version (unlike for a source
+/// tree), so we can tolerate dynamic versions.
+pub(crate) fn parse_pyproject_toml(
+    contents: &str,
+    sdist_version: Option<&Version>,
+) -> Result<ResolutionMetadata, MetadataError> {
     let pyproject_toml = PyProjectToml::from_toml(contents)?;
 
     let project = pyproject_toml
@@ -28,7 +34,11 @@ pub(crate) fn parse_pyproject_toml(contents: &str) -> Result<ResolutionMetadata,
                 return Err(MetadataError::DynamicField("optional-dependencies"))
             }
             "requires-python" => return Err(MetadataError::DynamicField("requires-python")),
-            "version" => return Err(MetadataError::DynamicField("version")),
+            // When building from a source distribution, the version is known from the filename and
+            // fixed by it, so we can pretend it's static.
+            "version" if sdist_version.is_none() => {
+                return Err(MetadataError::DynamicField("version"))
+            }
             _ => (),
         }
     }
@@ -44,6 +54,9 @@ pub(crate) fn parse_pyproject_toml(contents: &str) -> Result<ResolutionMetadata,
     let name = project.name;
     let version = project
         .version
+        // When building from a source distribution, the version is known from the filename and
+        // fixed by it, so we can pretend it's static.
+        .or_else(|| sdist_version.cloned())
         .ok_or(MetadataError::FieldNotFound("version"))?;
 
     // Parse the Python version requirements.
@@ -238,23 +251,23 @@ mod tests {
         [project]
         name = "asdf"
     "#;
-        let meta = parse_pyproject_toml(s);
+        let meta = parse_pyproject_toml(s, None);
         assert!(matches!(meta, Err(MetadataError::FieldNotFound("version"))));
 
         let s = r#"
         [project]
         name = "asdf"
         dynamic = ["version"]
     "#;
-        let meta = parse_pyproject_toml(s);
+        let meta = parse_pyproject_toml(s, None);
         assert!(matches!(meta, Err(MetadataError::DynamicField("version"))));
 
         let s = r#"
         [project]
         name = "asdf"
         version = "1.0"
     "#;
-        let meta = parse_pyproject_toml(s).unwrap();
+        let meta = parse_pyproject_toml(s, None).unwrap();
         assert_eq!(meta.name, PackageName::from_str("asdf").unwrap());
         assert_eq!(meta.version, Version::new([1, 0]));
         assert!(meta.requires_python.is_none());
@@ -267,7 +280,7 @@ mod tests {
         version = "1.0"
         requires-python = ">=3.6"
     "#;
-        let meta = parse_pyproject_toml(s).unwrap();
+        let meta = parse_pyproject_toml(s, None).unwrap();
         assert_eq!(meta.name, PackageName::from_str("asdf").unwrap());
         assert_eq!(meta.version, Version::new([1, 0]));
         assert_eq!(meta.requires_python, Some(">=3.6".parse().unwrap()));
@@ -281,7 +294,7 @@ mod tests {
         requires-python = ">=3.6"
         dependencies = ["foo"]
     "#;
-        let meta = parse_pyproject_toml(s).unwrap();
+        let meta = parse_pyproject_toml(s, None).unwrap();
         assert_eq!(meta.name, PackageName::from_str("asdf").unwrap());
         assert_eq!(meta.version, Version::new([1, 0]));
         assert_eq!(meta.requires_python, Some(">=3.6".parse().unwrap()));
@@ -298,7 +311,7 @@ mod tests {
         [project.optional-dependencies]
         dotenv = ["bar"]
     "#;
-        let meta = parse_pyproject_toml(s).unwrap();
+        let meta = parse_pyproject_toml(s, None).unwrap();
         assert_eq!(meta.name, PackageName::from_str("asdf").unwrap());
         assert_eq!(meta.version, Version::new([1, 0]));
         assert_eq!(meta.requires_python, Some(">=3.6".parse().unwrap()));