Allow non-root packages in uv sync

crates/uv-resolver/src/lock/installable.rs

@@ -65,7 +65,7 @@ pub trait Installable<'lock> {
             for root_name in self.roots() {
                 let dist = self
                     .lock()
-                    .find_by_name(root_name)
+                    .find_by_markers(root_name, marker_env.markers())
                     .map_err(|_| LockErrorKind::MultipleRootPackages {
                         name: root_name.clone(),
                     })?
@@ -97,7 +97,7 @@ pub trait Installable<'lock> {
         for root_name in self.roots() {
             let dist = self
                 .lock()
-                .find_by_name(root_name)
+                .find_by_markers(root_name, marker_env.markers())
                 .map_err(|_| LockErrorKind::MultipleRootPackages {
                     name: root_name.clone(),
                 })?

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

@@ -3,7 +3,7 @@ use std::ops::Deref;
 use std::path::Path;
 use std::sync::Arc;
 
-use anyhow::{Context, Result};
+use anyhow::Result;
 use itertools::Itertools;
 use owo_colors::OwoColorize;
 use serde::Serialize;
@@ -99,39 +99,15 @@ pub(crate) async fn sync(
         SyncTarget::Script(script)
     } else {
         // Identify the project.
-        let project = if frozen {
-            VirtualProject::discover(
-                project_dir,
-                &DiscoveryOptions {
-                    members: MemberDiscovery::None,
-                    ..DiscoveryOptions::default()
-                },
-                &workspace_cache,
-            )
-            .await?
-        } else if let [name] = package.as_slice() {
-            VirtualProject::Project(
-                Workspace::discover(project_dir, &DiscoveryOptions::default(), &workspace_cache)
-                    .await?
-                    .with_current_project(name.clone())
-                    .with_context(|| format!("Package `{name}` not found in workspace"))?,
-            )
-        } else {
-            let project = VirtualProject::discover(
-                project_dir,
-                &DiscoveryOptions::default(),
-                &workspace_cache,
-            )
-            .await?;
-
-            for name in &package {
-                if !project.workspace().packages().contains_key(name) {
-                    return Err(anyhow::anyhow!("Package `{name}` not found in workspace",));
-                }
+        let discovery = if frozen {
+            DiscoveryOptions {
+                members: MemberDiscovery::None,
+                ..DiscoveryOptions::default()
             }
-
-            project
+        } else {
+            DiscoveryOptions::default()
         };
+        let project = VirtualProject::discover(project_dir, &discovery, &workspace_cache).await?;
 
         // TODO(lucab): improve warning content
         // <https://github.com/astral-sh/uv/issues/7428>

crates/uv/tests/it/sync.rs

@@ -377,6 +377,96 @@ fn multiple_packages() -> Result<()> {
     Ok(())
 }
 
+/// Sync a non-workspace member.
+#[test]
+fn non_root() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "root"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = [
+            "anyio==4.3.0 ; sys_platform == 'darwin'",
+            "anyio==4.2.0 ; sys_platform == 'win32'",
+        ]
+        "#,
+    )?;
+
+    context.lock().assert().success();
+
+    uv_snapshot!(context.filters(), context.sync().arg("--package").arg("anyio"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 5 packages in [TIME]
+    Prepared 3 packages in [TIME]
+    Installed 3 packages in [TIME]
+     + anyio==4.3.0
+     + idna==3.6
+     + sniffio==1.3.1
+    ");
+
+    uv_snapshot!(context.filters(), context.sync().arg("--package").arg("iniconfig"), @r"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 5 packages in [TIME]
+    error: Could not find root package `iniconfig`
+    ");
+
+    Ok(())
+}
+
+/// Attempt to sync an ambiguous non-workspace member.
+#[test]
+fn non_root_non_unique() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "root"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+
+        [project.optional-dependencies]
+        foo = ["anyio==4.3.0"]
+        bar = ["anyio==4.2.0"]
+
+        [tool.uv]
+        conflicts = [
+            [
+              { extra = "foo" },
+              { extra = "bar" },
+            ],
+        ]
+        "#,
+    )?;
+
+    context.lock().assert().success();
+
+    uv_snapshot!(context.filters(), context.sync().arg("--package").arg("anyio"), @r"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 5 packages in [TIME]
+    error: Found multiple packages matching `anyio`
+    ");
+
+    Ok(())
+}
+
 /// Test json output
 #[test]
 fn sync_json() -> Result<()> {