Improve error messages for `uv pip install` with `--extra` or `--all-extras` and invalid sources (#11193)

Closes https://github.com/astral-sh/uv/issues/11190
Closes https://github.com/astral-sh/uv/issues/7845

This error message was copied over from `uv pip compile` (presumably)
but makes way more sense there than here.

crates/uv/src/commands/pip/operations.rs

@@ -60,8 +60,18 @@ pub(crate) async fn read_requirements(
     // If the user requests `extras` but does not provide a valid source (e.g., a `pyproject.toml`),
     // return an error.
     if !extras.is_empty() && !requirements.iter().any(RequirementsSource::allows_extras) {
+        let hint = if requirements.iter().any(|source| {
+            matches!(
+                source,
+                RequirementsSource::Editable(_) | RequirementsSource::SourceTree(_)
+            )
+        }) {
+            "Use `<dir>[extra]` syntax or `-r <file>` instead."
+        } else {
+            "Use `package[extra]` syntax instead."
+        };
         return Err(anyhow!(
-            "Requesting extras requires a `pyproject.toml`, `setup.cfg`, or `setup.py` file."
+            "Requesting extras requires a `pyproject.toml`, `setup.cfg`, or `setup.py` file. {hint}"
         )
         .into());
     }

crates/uv/tests/it/pip_install.rs

@@ -1031,6 +1031,83 @@ fn allow_incompatibilities() -> Result<()> {
     Ok(())
 }
 
+#[test]
+fn install_extras() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    // Request extras for an editable path
+    uv_snapshot!(context.filters(), context.pip_install()
+        .arg("--all-extras")
+        .arg("-e")
+        .arg(context.workspace_root.join("scripts/packages/poetry_editable")), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: Requesting extras requires a `pyproject.toml`, `setup.cfg`, or `setup.py` file. Use `<dir>[extra]` syntax or `-r <file>` instead.
+    "###
+    );
+
+    // Request extras for a source tree
+    uv_snapshot!(context.filters(), context.pip_install()
+        .arg("--all-extras")
+        .arg(context.workspace_root.join("scripts/packages/poetry_editable")), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: Requesting extras requires a `pyproject.toml`, `setup.cfg`, or `setup.py` file. Use `package[extra]` syntax instead.
+    "###
+    );
+
+    let requirements_txt = context.temp_dir.child("requirements.txt");
+    requirements_txt.write_str("anyio==3.7.0")?;
+
+    // Request extras for a requirements file
+    uv_snapshot!(context.filters(), context.pip_install()
+        .arg("--all-extras")
+        .arg("-r").arg("requirements.txt"), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: Requesting extras requires a `pyproject.toml`, `setup.cfg`, or `setup.py` file. Use `package[extra]` syntax instead.
+    "###
+    );
+
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+[project]
+name = "project"
+version = "0.1.0"
+dependencies = ["anyio==3.7.0"]
+"#,
+    )?;
+
+    uv_snapshot!(context.filters(), context.pip_install()
+        .arg("--all-extras")
+        .arg("-r").arg("pyproject.toml"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 3 packages in [TIME]
+    Prepared 3 packages in [TIME]
+    Installed 3 packages in [TIME]
+     + anyio==3.7.0
+     + idna==3.6
+     + sniffio==1.3.1
+    "###
+    );
+
+    Ok(())
+}
+
 #[test]
 fn install_editable() {
     let context = TestContext::new("3.12");