Make ignored key in config be an error

Signed-off-by: hi-rustin <[email protected]>

Author: 0xPoe

src/cargo/util/toml/mod.rs

@@ -1734,12 +1734,11 @@ impl<P: ResolveToPath> DetailedTomlDependency<P> {
 
             for &(key, key_name) in &git_only_keys {
                 if key.is_some() {
-                    let msg = format!(
-                        "key `{}` is ignored for dependency ({}). \
-                         This will be considered an error in future versions",
-                        key_name, name_in_toml
+                    bail!(
+                        "key `{}` is ignored for dependency ({}).",
+                        key_name,
+                        name_in_toml
                     );
-                    cx.warnings.push(msg)
                 }
             }
         }

tests/testsuite/bad_config.rs

@@ -1183,9 +1183,13 @@ fn ignored_git_revision() {
 
     foo.cargo("build -v")
         .with_status(101)
-        .with_stderr_contains(
-            "[WARNING] key `branch` is ignored for dependency (bar). \
-             This will be considered an error in future versions",
+        .with_stderr(
+            "\
+error: failed to parse manifest at `[..]`
+
+Caused by:
+  key `branch` is ignored for dependency (bar).
+",
         )
         .run();
 }