Add uv sync --script

crates/uv-cli/src/lib.rs

@@ -3135,6 +3135,20 @@ pub struct SyncArgs {
     #[arg(long, conflicts_with = "all_packages")]
     pub package: Option<PackageName>,
 
+    /// Sync the virtual environment for the specified PEP 723 Python script, rather than the current
+    /// project.
+    ///
+    /// If provided, uv will sync the dependencies based on the script's inline metadata table, in
+    /// adherence with PEP 723.
+    #[arg(
+        long,
+        conflicts_with = "all_packages",
+        conflicts_with = "package",
+        conflicts_with = "no_install_project",
+        conflicts_with = "no_install_workspace"
+    )]
+    pub script: Option<PathBuf>,
+
     /// The Python interpreter to use for the project environment.
     ///
     /// By default, the first interpreter that meets the project's `requires-python` constraint is

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

@@ -1155,9 +1155,23 @@ impl ProjectEnvironment {
     }
 }
 
-/// The Python environment for a project.
+/// The Python environment for a script.
 #[derive(Debug)]
-struct ScriptEnvironment(PythonEnvironment);
+enum ScriptEnvironment {
+    /// An existing [`PythonEnvironment`] was discovered, which satisfies the script's requirements.
+    Existing(PythonEnvironment),
+    /// An existing [`PythonEnvironment`] was discovered, but did not satisfy the script's
+    /// requirements, and so was replaced.
+    ///
+    /// In `--dry-run` mode, the environment will not be replaced, but this variant will still be
+    /// returned.
+    Replaced(PythonEnvironment, PathBuf),
+    /// A new [`PythonEnvironment`] was created.
+    ///
+    /// In `--dry-run` mode, the environment will not be created, but this variant will still be
+    /// returned.
+    New(PythonEnvironment, PathBuf),
+}
 
 impl ScriptEnvironment {
     /// Initialize a virtual environment for a PEP 723 script.
@@ -1172,6 +1186,7 @@ impl ScriptEnvironment {
         install_mirrors: &PythonInstallMirrors,
         no_config: bool,
         cache: &Cache,
+        dry_run: DryRun,
         printer: Printer,
     ) -> Result<Self, ProjectError> {
         // Lock the script environment to avoid synchronization issues.
@@ -1193,23 +1208,34 @@ impl ScriptEnvironment {
         .await?
         {
             // If we found an existing, compatible environment, use it.
-            ScriptInterpreter::Environment(environment) => Ok(Self(environment)),
+            ScriptInterpreter::Environment(environment) => Ok(Self::Existing(environment)),
 
             // Otherwise, create a virtual environment with the discovered interpreter.
             ScriptInterpreter::Interpreter(interpreter) => {
                 let root = cache
                     .shard(CacheBucket::Environments, cache_digest(&script.path))
                     .into_path_buf();
 
+                // Under `--dry-run`, avoid modifying the environment.
+                if dry_run.enabled() {
+                    let environment = PythonEnvironment::from_interpreter(interpreter);
+                    return Ok(if root.exists() {
+                        Self::Replaced(environment, root)
+                    } else {
+                        Self::New(environment, root)
+                    });
+                }
+
                 // Remove the existing virtual environment.
-                match fs_err::remove_dir_all(&root) {
+                let replaced = match fs_err::remove_dir_all(&root) {
                     Ok(()) => {
                         debug!(
                             "Removed virtual environment at: {}",
                             root.user_display().cyan()
                         );
+                        true
                     }
-                    Err(err) if err.kind() == std::io::ErrorKind::NotFound => {}
+                    Err(err) if err.kind() == std::io::ErrorKind::NotFound => false,
                     Err(err) => return Err(err.into()),
                 };
 
@@ -1239,14 +1265,22 @@ impl ScriptEnvironment {
                     false,
                 )?;
 
-                Ok(Self(environment))
+                Ok(if replaced {
+                    Self::Replaced(environment, root)
+                } else {
+                    Self::New(environment, root)
+                })
             }
         }
     }
 
     /// Convert the [`ScriptEnvironment`] into a [`PythonEnvironment`].
     pub(crate) fn into_environment(self) -> PythonEnvironment {
-        self.0
+        match self {
+            Self::Existing(environment) => environment,
+            Self::Replaced(environment, ..) => environment,
+            Self::New(environment, ..) => environment,
+        }
     }
 }
 

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

@@ -211,6 +211,7 @@ pub(crate) async fn run(
                 &install_mirrors,
                 no_config,
                 cache,
+                DryRun::Disabled,
                 printer,
             )
             .await?
@@ -422,6 +423,7 @@ pub(crate) async fn run(
                         &install_mirrors,
                         no_config,
                         cache,
+                        DryRun::Disabled,
                         printer,
                     )
                     .await?