Block scripts from overwriting python (#13051)

uv adds some binaries and scripts to a venv, and installed packages
should not be allowed to overwrite them.

Fixes #12983

crates/uv-install-wheel/src/lib.rs

@@ -82,4 +82,6 @@ pub enum Error {
     InvalidEggLink(PathBuf),
     #[error(transparent)]
     LauncherError(#[from] uv_trampoline_builder::Error),
+    #[error("Scripts must not use the reserved name {0}")]
+    ReservedScriptName(String),
 }

crates/uv-install-wheel/src/wheel.rs

@@ -18,6 +18,7 @@ use uv_normalize::PackageName;
 use uv_pypi_types::DirectUrl;
 use uv_shell::escape_posix_for_single_quotes;
 use uv_trampoline_builder::windows_script_launcher;
+use uv_warnings::warn_user_once;
 
 use crate::record::RecordEntry;
 use crate::script::{scripts_from_ini, Script};
@@ -186,6 +187,25 @@ pub(crate) fn write_script_entrypoints(
     is_gui: bool,
 ) -> Result<(), Error> {
     for entrypoint in entrypoints {
+        let warn_names = ["activate", "activate_this.py"];
+        if warn_names.contains(&entrypoint.name.as_str())
+            || entrypoint.name.starts_with("activate.")
+        {
+            warn_user_once!(
+                "The script name `{}` is reserved for virtual environment activation scripts.",
+                entrypoint.name
+            );
+        }
+        let reserved_names = ["python", "pythonw", "python3"];
+        if reserved_names.contains(&entrypoint.name.as_str())
+            || entrypoint
+                .name
+                .strip_prefix("python3.")
+                .is_some_and(|suffix| suffix.parse::<u8>().is_ok())
+        {
+            return Err(Error::ReservedScriptName(entrypoint.name.clone()));
+        }
+
         let entrypoint_absolute = entrypoint_path(entrypoint, layout);
 
         let entrypoint_relative = pathdiff::diff_paths(&entrypoint_absolute, site_packages)

crates/uv/tests/it/pip_install.rs

@@ -11161,3 +11161,78 @@ async fn bogus_redirect() -> Result<()> {
 
     Ok(())
 }
+
+#[test]
+fn reserved_script_name() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+
+        [project.scripts]
+        "activate.bash" = "project:activate"
+
+        [build-system]
+        requires = ["hatchling"]
+        build-backend = "hatchling.build"
+    "#,
+    )?;
+
+    context
+        .temp_dir
+        .child("src")
+        .child("project")
+        .child("__init__.py")
+        .touch()?;
+
+    uv_snapshot!(context.filters(), context.pip_install().arg("."), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 1 package in [TIME]
+    Prepared 1 package in [TIME]
+    warning: The script name `activate.bash` is reserved for virtual environment activation scripts.
+    Installed 1 package in [TIME]
+     + project==0.1.0 (from file://[TEMP_DIR]/)
+    "
+    );
+
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+
+        [project.scripts]
+        "python" = "project:python"
+
+        [build-system]
+        requires = ["hatchling"]
+        build-backend = "hatchling.build"
+    "#,
+    )?;
+
+    uv_snapshot!(context.filters(), context.pip_install().arg("."), @r"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 1 package in [TIME]
+    Prepared 1 package in [TIME]
+    Uninstalled 1 package in [TIME]
+    error: Failed to install: project-0.1.0-py3-none-any.whl (project==0.1.0 (from file://[TEMP_DIR]/))
+      Caused by: Scripts must not use the reserved name python
+    "
+    );
+
+    Ok(())
+}