Add warnings for undefined groups

Author: Gankra

crates/uv-requirements/src/source_tree.rs

@@ -18,7 +18,7 @@ use uv_pep508::RequirementOrigin;
 use uv_pypi_types::Requirement;
 use uv_resolver::{InMemoryIndex, MetadataResponse};
 use uv_types::{BuildContext, HashStrategy};
-
+use uv_warnings::warn_user_once;
 #[derive(Debug, Clone)]
 pub struct SourceTreeResolution {
     /// The requirements sourced from the source trees.
@@ -115,6 +115,20 @@ impl<'a, Context: BuildContext> SourceTreeResolver<'a, Context> {
                 requirements.extend(group.iter().cloned());
             }
         }
+        // Complain if dependency groups are named that don't appear.
+        // This is only a warning because *technically* we support passing in
+        // multiple pyproject.tomls, but at this level of abstraction we can't see them all,
+        // so hard erroring on "no pyproject.toml mentions this" is a bit difficult.
+        if let Some(groups) = self.groups.groups() {
+            for name in groups.names() {
+                if !metadata.dependency_groups.contains_key(name) {
+                    warn_user_once!(
+                        "The dependency-group '{name}' is not defined in {}",
+                        path.display()
+                    );
+                }
+            }
+        }
 
         let project = metadata.name;
         let extras = metadata.provides_extras;

crates/uv/tests/it/pip_install.rs

@@ -8610,13 +8610,30 @@ fn install_many_pyproject_group() -> Result<()> {
     ----- stdout -----
 
     ----- stderr -----
+    warning: The dependency-group 'bar' is not defined in pyproject.toml
     Resolved 2 packages in [TIME]
     Prepared 2 packages in [TIME]
     Installed 2 packages in [TIME]
      + sniffio==1.3.1
      + typing-extensions==4.10.0
     "###);
 
+    context = new_context()?;
+    uv_snapshot!(context.filters(), context.pip_install().arg("-r")
+    .arg("pyproject.toml").arg("-r").arg("subdir/pyproject.toml").arg("--group").arg("lies"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    warning: The dependency-group 'lies' is not defined in pyproject.toml
+    warning: The dependency-group 'lies' is not defined in subdir/pyproject.toml
+    Resolved 1 package in [TIME]
+    Prepared 1 package in [TIME]
+    Installed 1 package in [TIME]
+     + typing-extensions==4.10.0
+    "###);
+
     context = new_context()?;
     uv_snapshot!(context.filters(), context.pip_install().arg("-r")
     .arg("pyproject.toml").arg("-r").arg("subdir/pyproject.toml").arg("--group").arg("foo").arg("--group").arg("bar"), @r###"
@@ -8625,6 +8642,7 @@ fn install_many_pyproject_group() -> Result<()> {
     ----- stdout -----
 
     ----- stderr -----
+    warning: The dependency-group 'bar' is not defined in pyproject.toml
     Resolved 4 packages in [TIME]
     Prepared 4 packages in [TIME]
     Installed 4 packages in [TIME]