Distinguish exported vs private header dirs in logging
diff --git a/gen/build/src/lib.rs b/gen/build/src/lib.rs
index df2ffad..783eb04 100644
--- a/gen/build/src/lib.rs
+++ b/gen/build/src/lib.rs
@@ -226,7 +226,11 @@
     for krate in crates {
         for header_dir in &krate.header_dirs {
             build.include(&header_dir.path);
-            eprintln!("  {}", header_dir.path.display());
+            if header_dir.exported {
+                eprintln!("  {}", header_dir.path.display());
+            } else {
+                eprintln!("  {} (private)", header_dir.path.display());
+            }
         }
     }