check that the Tracking issue row points to rust-project-goals repo

Author: lqd

crates/rust-project-goals/src/goal.rs

@@ -451,6 +451,15 @@ fn extract_metadata(sections: &[Section]) -> Result<Option<Metadata>> {
             spanned::bail!(r[1], "accepted goals cannot have an empty tracking issue");
         }
 
+        if has_tracking_issue && !r[1].contains("rust-project-goals#") {
+            spanned::bail!(
+                r[1],
+                "tracking issues are issues in the rust-project-goals repository. \
+                The `{}` issue can go in the `Other tracking issues` row.",
+                r[1].as_str(),
+            );
+        }
+
         // For the others, it's of course optional.
         if has_tracking_issue {
             Some(r[1].parse()?.content)