Require explicitly selection of workspace root groups when a workspace member is active

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

@@ -96,16 +96,27 @@ pub(crate) async fn export(
         ExportTarget::Script(script)
     } else {
         let project = if frozen.is_some() {
-            VirtualProject::discover(
-                project_dir,
-                &DiscoveryOptions {
-                    members: MemberDiscovery::None,
-                    ..DiscoveryOptions::default()
+            let options = DiscoveryOptions {
+                members: if package.is_empty() {
+                    MemberDiscovery::None
+                } else {
+                    MemberDiscovery::Existing
                 },
-                cache,
-                workspace_cache,
-            )
-            .await?
+                ..DiscoveryOptions::default()
+            };
+
+            if let [name] = package.as_slice() {
+                VirtualProject::discover_with_package(
+                    project_dir,
+                    &options,
+                    cache,
+                    workspace_cache,
+                    name.clone(),
+                )
+                .await?
+            } else {
+                VirtualProject::discover(project_dir, &options, cache, workspace_cache).await?
+            }
         } else if let [name] = package.as_slice() {
             VirtualProject::discover_with_package(
                 project_dir,

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

@@ -151,6 +151,12 @@ impl<'lock> Installable<'lock> for InstallTarget<'lock> {
             return true;
         }
 
+        // Workspace-root groups must be requested explicitly when a member is selected.
+        // Defaults belong to the selected member, not to an inherited workspace root.
+        if groups.contains_because_default(group) {
+            return false;
+        }
+
         !workspace.packages().get(*name).is_some_and(|member| {
             let pyproject = member.pyproject_toml();
             pyproject

crates/uv/tests/project/export.rs

@@ -1051,7 +1051,6 @@ fn requirements_txt_workspace_member_ignores_root_default_group() -> Result<()>
         .arg("--package").arg("child"), @"
     exit_code: 0 (success)
     ----- stdout -----
-    iniconfig==2.0.0
     typing-extensions==4.10.0
     ");
 
@@ -1062,7 +1061,6 @@ fn requirements_txt_workspace_member_ignores_root_default_group() -> Result<()>
         .arg("--package").arg("child"), @"
     exit_code: 0 (success)
     ----- stdout -----
-    iniconfig==2.0.0
     typing-extensions==4.10.0
 
     ----- stderr -----
@@ -1134,7 +1132,6 @@ fn requirements_txt_frozen_workspace_member_group_precedence() -> Result<()> {
     exit_code: 0 (success)
     ----- stdout -----
     iniconfig==2.0.0
-    sniffio==1.3.1
     typing-extensions==4.10.0
     ");
 
@@ -1148,7 +1145,6 @@ fn requirements_txt_frozen_workspace_member_group_precedence() -> Result<()> {
     exit_code: 0 (success)
     ----- stdout -----
     iniconfig==2.0.0
-    sniffio==1.3.1
     typing-extensions==4.10.0
     ");
 
@@ -1163,7 +1159,6 @@ fn requirements_txt_frozen_workspace_member_group_precedence() -> Result<()> {
     ----- stdout -----
     idna==3.6
     iniconfig==2.0.0
-    sniffio==1.3.1
     typing-extensions==4.10.0
     ");
 

crates/uv/tests/project/run.rs

@@ -6577,13 +6577,12 @@ fn run_target_workspace_discovery_workspace_group_defaults() -> Result<()> {
         .arg("child/scripts/groups.py"), @"
     exit_code: 0 (success)
     ----- stdout -----
-    installed: typing_extensions, sniffio
+    installed: typing_extensions
 
     ----- stderr -----
     Resolved 6 packages in [TIME]
-    Prepared 2 packages in [TIME]
-    Installed 2 packages in [TIME]
-     + sniffio==1.3.1
+    Prepared 1 package in [TIME]
+    Installed 1 package in [TIME]
      + typing-extensions==4.10.0
     ");
 

crates/uv/tests/sync/sync.rs

@@ -1348,12 +1348,38 @@ fn sync_non_project_dev_dependencies() -> Result<()> {
      + urllib3==2.2.1
     ");
 
-    // Selecting a member still includes the non-project root's default dependency group.
+    // Selecting a member excludes the non-project root's default dependency group.
     uv_snapshot!(context.filters(), context.sync().arg("--package").arg("child"), @"
     exit_code: 0 (success)
     ----- stderr -----
     Resolved 11 packages in [TIME]
-    Checked 10 packages in [TIME]
+    Uninstalled 8 packages in [TIME]
+     - anyio==4.3.0
+     - certifi==2024.2.2
+     - charset-normalizer==3.3.2
+     - idna==3.6
+     - pysocks==1.7.1
+     - requests==2.31.0
+     - sniffio==1.3.1
+     - urllib3==2.2.1
+    ");
+
+    // Explicitly requesting the root's group still includes its dependencies.
+    uv_snapshot!(context.filters(), context.sync()
+        .arg("--package").arg("child")
+        .arg("--group").arg("dev"), @"
+    exit_code: 0 (success)
+    ----- stderr -----
+    Resolved 11 packages in [TIME]
+    Installed 8 packages in [TIME]
+     + anyio==4.3.0
+     + certifi==2024.2.2
+     + charset-normalizer==3.3.2
+     + idna==3.6
+     + pysocks==1.7.1
+     + requests==2.31.0
+     + sniffio==1.3.1
+     + urllib3==2.2.1
     ");
 
     Ok(())