Error when editables don't match Requires-Python (#2194)

## Summary

Closes https://github.com/astral-sh/uv/issues/2192.

## Test Plan

(Needs tests.)

crates/uv-resolver/src/python_requirement.rs

@@ -22,12 +22,12 @@ impl PythonRequirement {
     }
 
     /// Return the installed version of Python.
-    pub(crate) fn installed(&self) -> &Version {
+    pub fn installed(&self) -> &Version {
         &self.installed
     }
 
     /// Return the target version of Python.
-    pub(crate) fn target(&self) -> &Version {
+    pub fn target(&self) -> &Version {
         &self.target
     }
 

crates/uv/src/commands/pip_compile.rs

@@ -29,7 +29,7 @@ use uv_interpreter::{Interpreter, PythonVersion};
 use uv_normalize::{ExtraName, PackageName};
 use uv_resolver::{
     AnnotationStyle, DependencyMode, DisplayResolutionGraph, InMemoryIndex, Manifest,
-    OptionsBuilder, PreReleaseMode, ResolutionMode, Resolver,
+    OptionsBuilder, PreReleaseMode, PythonRequirement, ResolutionMode, Resolver,
 };
 use uv_traits::{ConfigSettings, InFlight, NoBuild, SetupPyStrategy};
 use uv_warnings::warn_user;
@@ -244,8 +244,9 @@ pub(crate) async fn pip_compile(
         let downloader = Downloader::new(&cache, &tags, &client, &build_dispatch)
             .with_reporter(DownloadReporter::from(printer).with_length(editables.len() as u64));
 
+        // Build all editables.
         let editable_wheel_dir = tempdir_in(cache.root())?;
-        let editable_metadata: Vec<_> = downloader
+        let editables: Vec<_> = downloader
             .build_editables(editables, editable_wheel_dir.path())
             .await
             .context("Failed to build editables")?
@@ -253,22 +254,33 @@ pub(crate) async fn pip_compile(
             .map(|built_editable| (built_editable.editable, built_editable.metadata))
             .collect();
 
-        let s = if editable_metadata.len() == 1 {
-            ""
-        } else {
-            "s"
-        };
+        // Validate that the editables are compatible with the target Python version.
+        let requirement = PythonRequirement::new(&interpreter, &markers);
+        for (.., metadata) in &editables {
+            if let Some(python_requires) = metadata.requires_python.as_ref() {
+                if !python_requires.contains(requirement.target()) {
+                    return Err(anyhow!(
+                        "Editable `{}` requires Python {}, but resolution targets Python {}",
+                        metadata.name,
+                        python_requires,
+                        requirement.target()
+                    ));
+                }
+            }
+        }
+
+        let s = if editables.len() == 1 { "" } else { "s" };
         writeln!(
             printer,
             "{}",
             format!(
                 "Built {} in {}",
-                format!("{} editable{}", editable_metadata.len(), s).bold(),
+                format!("{} editable{}", editables.len(), s).bold(),
                 elapsed(start.elapsed())
             )
             .dimmed()
         )?;
-        editable_metadata
+        editables
     };
 
     // Create a manifest of the requirements.

crates/uv/src/commands/pip_install.rs

@@ -215,6 +215,7 @@ pub(crate) async fn pip_install(
             &editables,
             editable_wheel_dir.path(),
             &cache,
+            &interpreter,
             tags,
             &client,
             &resolve_dispatch,
@@ -356,10 +357,12 @@ fn specification(
 }
 
 /// Build a set of editable distributions.
+#[allow(clippy::too_many_arguments)]
 async fn build_editables(
     editables: &[EditableRequirement],
     editable_wheel_dir: &Path,
     cache: &Cache,
+    interpreter: &Interpreter,
     tags: &Tags,
     client: &RegistryClient,
     build_dispatch: &BuildDispatch<'_>,
@@ -389,6 +392,21 @@ async fn build_editables(
         .into_iter()
         .collect();
 
+    // Validate that the editables are compatible with the target Python version.
+    for editable in &editables {
+        if let Some(python_requires) = editable.metadata.requires_python.as_ref() {
+            if !python_requires.contains(interpreter.python_version()) {
+                return Err(anyhow!(
+                    "Editable `{}` requires Python {}, but {} is installed",
+                    editable.metadata.name,
+                    python_requires,
+                    interpreter.python_version()
+                )
+                .into());
+            }
+        }
+    }
+
     let s = if editables.len() == 1 { "" } else { "s" };
     writeln!(
         printer,

crates/uv/src/commands/pip_sync.rs

@@ -1,6 +1,6 @@
 use std::fmt::Write;
 
-use anyhow::{Context, Result};
+use anyhow::{anyhow, Context, Result};
 use itertools::Itertools;
 use owo_colors::OwoColorize;
 use tracing::debug;
@@ -18,7 +18,7 @@ use uv_fs::Simplified;
 use uv_installer::{
     is_dynamic, Downloader, NoBinary, Plan, Planner, Reinstall, ResolvedEditable, SitePackages,
 };
-use uv_interpreter::PythonEnvironment;
+use uv_interpreter::{Interpreter, PythonEnvironment};
 use uv_resolver::InMemoryIndex;
 use uv_traits::{ConfigSettings, InFlight, NoBuild, SetupPyStrategy};
 
@@ -151,7 +151,7 @@ pub(crate) async fn pip_sync(
         editables,
         &site_packages,
         reinstall,
-        &venv,
+        venv.interpreter(),
         tags,
         &cache,
         &client,
@@ -413,7 +413,7 @@ async fn resolve_editables(
     editables: Vec<EditableRequirement>,
     site_packages: &SitePackages<'_>,
     reinstall: &Reinstall,
-    venv: &PythonEnvironment,
+    interpreter: &Interpreter,
     tags: &Tags,
     cache: &Cache,
     client: &RegistryClient,
@@ -479,7 +479,7 @@ async fn resolve_editables(
     } else {
         let start = std::time::Instant::now();
 
-        let temp_dir = tempfile::tempdir_in(venv.root())?;
+        let temp_dir = tempfile::tempdir_in(cache.root())?;
 
         let downloader = Downloader::new(cache, tags, client, build_dispatch)
             .with_reporter(DownloadReporter::from(printer).with_length(uninstalled.len() as u64));
@@ -503,6 +503,20 @@ async fn resolve_editables(
             .into_iter()
             .collect();
 
+        // Validate that the editables are compatible with the target Python version.
+        for editable in &built_editables {
+            if let Some(python_requires) = editable.metadata.requires_python.as_ref() {
+                if !python_requires.contains(interpreter.python_version()) {
+                    return Err(anyhow!(
+                        "Editable `{}` requires Python {}, but {} is installed",
+                        editable.metadata.name,
+                        python_requires,
+                        interpreter.python_version()
+                    ));
+                }
+            }
+        }
+
         let s = if built_editables.len() == 1 { "" } else { "s" };
         writeln!(
             printer,

crates/uv/tests/pip_compile.rs

@@ -4670,3 +4670,89 @@ fn expand_env_var_requirements_txt() -> Result<()> {
 
     Ok(())
 }
+
+/// Raise an error when an editable's `Requires-Python` constraint is not met.
+#[test]
+fn requires_python_editable() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    // Create an editable package with a `Requires-Python` constraint that is not met.
+    let editable_dir = TempDir::new()?;
+    let pyproject_toml = editable_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"[project]
+name = "example"
+version = "0.0.0"
+dependencies = [
+  "anyio==4.0.0"
+]
+requires-python = "<=3.8"
+"#,
+    )?;
+
+    // Write to a requirements file.
+    let requirements_in = context.temp_dir.child("requirements.in");
+    requirements_in.write_str(&format!("-e {}", editable_dir.path().display()))?;
+
+    uv_snapshot!(context.compile()
+        .arg("requirements.in"), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: Editable `example` requires Python <=3.8, but resolution targets Python 3.12.1
+    "###
+    );
+
+    Ok(())
+}
+
+/// Raise an error when an editable's `Requires-Python` constraint is not met.
+#[test]
+fn requires_python_editable_target_version() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    // Create an editable package with a `Requires-Python` constraint that is not met.
+    let editable_dir = TempDir::new()?;
+    let pyproject_toml = editable_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"[project]
+name = "example"
+version = "0.0.0"
+dependencies = [
+  "anyio==4.0.0"
+]
+requires-python = "<=3.8"
+"#,
+    )?;
+
+    // Write to a requirements file.
+    let requirements_in = context.temp_dir.child("requirements.in");
+    requirements_in.write_str(&format!("-e {}", editable_dir.path().display()))?;
+
+    let filters: Vec<_> = [
+        // 3.11 may not be installed
+        (
+            "warning: The requested Python version 3.11 is not available; .* will be used to build dependencies instead.\n",
+            "",
+        ),
+    ]
+        .into_iter()
+        .chain(INSTA_FILTERS.to_vec())
+        .collect();
+
+    uv_snapshot!(filters, context.compile()
+        .arg("requirements.in")
+        .arg("--python-version=3.11"), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: Editable `example` requires Python <=3.8, but resolution targets Python 3.11
+    "###
+    );
+
+    Ok(())
+}

crates/uv/tests/pip_install.rs

@@ -2247,3 +2247,37 @@ requires-python = ">=3.11,<3.13"
 
     Ok(())
 }
+
+/// Raise an error when an editable's `Requires-Python` constraint is not met.
+#[test]
+fn requires_python_editable() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    // Create an editable package with a `Requires-Python` constraint that is not met.
+    let editable_dir = assert_fs::TempDir::new()?;
+    let pyproject_toml = editable_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"[project]
+name = "example"
+version = "0.0.0"
+dependencies = [
+  "anyio==4.0.0"
+]
+requires-python = "<=3.8"
+"#,
+    )?;
+
+    uv_snapshot!(command(&context)
+        .arg("--editable")
+        .arg(editable_dir.path()), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: Editable `example` requires Python <=3.8, but 3.12.1 is installed
+    "###
+    );
+
+    Ok(())
+}

crates/uv/tests/pip_sync.rs

@@ -2956,3 +2956,40 @@ fn compile() -> Result<()> {
 
     Ok(())
 }
+
+/// Raise an error when an editable's `Requires-Python` constraint is not met.
+#[test]
+fn requires_python_editable() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    // Create an editable package with a `Requires-Python` constraint that is not met.
+    let editable_dir = assert_fs::TempDir::new()?;
+    let pyproject_toml = editable_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"[project]
+name = "example"
+version = "0.0.0"
+dependencies = [
+  "anyio==4.0.0"
+]
+requires-python = "<=3.5"
+"#,
+    )?;
+
+    // Write to a requirements file.
+    let requirements_in = context.temp_dir.child("requirements.in");
+    requirements_in.write_str(&format!("-e {}", editable_dir.path().display()))?;
+
+    uv_snapshot!(command(&context)
+        .arg("requirements.in"), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: Editable `example` requires Python <=3.5, but 3.12.1 is installed
+    "###
+    );
+
+    Ok(())
+}