Warn/err on some unused manifest keys in workspaces.

src/cargo/core/workspace.rs

@@ -658,18 +658,28 @@ impl<'cfg> Workspace<'cfg> {
             for pkg in self.members()
                 .filter(|p| p.manifest_path() != root_manifest)
             {
-                if pkg.manifest().original().has_profiles() {
-                    let message = &format!(
-                        "profiles for the non root package will be ignored, \
-                         specify profiles at the workspace root:\n\
+                let manifest = pkg.manifest();
+                let emit_warning = |what| -> CargoResult<()> {
+                    let msg = format!(
+                        "{} for the non root package will be ignored, \
+                         specify {} at the workspace root:\n\
                          package:   {}\n\
                          workspace: {}",
+                        what,
+                        what,
                         pkg.manifest_path().display(),
-                        root_manifest.display()
+                        root_manifest.display(),
                     );
-
-                    //TODO: remove `Eq` bound from `Profiles` when the warning is removed.
-                    self.config.shell().warn(&message)?;
+                    self.config.shell().warn(&msg)
+                };
+                if manifest.original().has_profiles() {
+                    emit_warning("profiles")?;
+                }
+                if !manifest.replace().is_empty() {
+                    emit_warning("replace")?;
+                }
+                if !manifest.patch().is_empty() {
+                    emit_warning("patch")?;
                 }
             }
         }

src/cargo/util/toml/mod.rs

@@ -1086,6 +1086,24 @@ impl TomlManifest {
         if me.bench.is_some() {
             bail!("virtual manifests do not specify [[bench]]");
         }
+        if me.dependencies.is_some() {
+            bail!("virtual manifests do not specify [dependencies]");
+        }
+        if me.dev_dependencies.is_some() || me.dev_dependencies2.is_some() {
+            bail!("virtual manifests do not specify [dev-dependencies]");
+        }
+        if me.build_dependencies.is_some() || me.build_dependencies2.is_some() {
+            bail!("virtual manifests do not specify [build-dependencies]");
+        }
+        if me.features.is_some() {
+            bail!("virtual manifests do not specify [features]");
+        }
+        if me.target.is_some() {
+            bail!("virtual manifests do not specify [target]");
+        }
+        if me.badges.is_some() {
+            bail!("virtual manifests do not specify [badges]");
+        }
 
         let mut nested_paths = Vec::new();
         let mut warnings = Vec::new();

tests/testsuite/workspaces.rs

@@ -1879,3 +1879,93 @@ fn ws_rustc_err() {
         .with_stderr("[ERROR] [..]against an actual package[..]")
         .run();
 }
+
+#[test]
+fn ws_err_unused() {
+    for key in &[
+        "[lib]",
+        "[[bin]]",
+        "[[example]]",
+        "[[test]]",
+        "[[bench]]",
+        "[dependencies]",
+        "[dev-dependencies]",
+        "[build-dependencies]",
+        "[features]",
+        "[target]",
+        "[badges]",
+    ] {
+        let p = project()
+            .file(
+                "Cargo.toml",
+                &format!(
+                    r#"
+                    [workspace]
+                    members = ["a"]
+
+                    {}
+                    "#,
+                    key
+                ),
+            )
+            .file("a/Cargo.toml", &basic_lib_manifest("a"))
+            .file("a/src/lib.rs", "")
+            .build();
+        p.cargo("check")
+            .with_status(101)
+            .with_stderr(&format!(
+                "\
+[ERROR] failed to parse manifest at `[..]/foo/Cargo.toml`
+
+Caused by:
+  virtual manifests do not specify {}
+",
+                key
+            ))
+            .run();
+    }
+}
+
+#[test]
+fn ws_warn_unused() {
+    for (key, name) in &[
+        ("[profile.dev]\nopt-level = 1", "profiles"),
+        ("[replace]\n\"bar:0.1.0\" = { path = \"bar\" }", "replace"),
+        ("[patch.crates-io]\nbar = { path = \"bar\" }", "patch"),
+    ] {
+        let p = project()
+            .file(
+                "Cargo.toml",
+                r#"
+                [workspace]
+                members = ["a"]
+                "#,
+            )
+            .file(
+                "a/Cargo.toml",
+                &format!(
+                    r#"
+                    [package]
+                    name = "a"
+                    version = "0.1.0"
+
+                    {}
+                    "#,
+                    key
+                ),
+            )
+            .file("a/src/lib.rs", "")
+            .build();
+        p.cargo("check")
+            .with_status(0)
+            .with_stderr_contains(&format!(
+                "\
+[WARNING] {} for the non root package will be ignored, specify {} at the workspace root:
+package:   [..]/foo/a/Cargo.toml
+workspace: [..]/foo/Cargo.toml
+",
+                name, name
+            ))
+            .run();
+    }
+}