Define PD_INTERNAL as true

build.rs

@@ -240,7 +240,7 @@ fn main() {
         .clang_arg(format!("-I{}", libpd_wrapper_dir.to_str().unwrap()))
         .clang_arg(format!("-I{}", pd_source.to_str().unwrap()))
         .clang_arg(format!("-DPD_FLOATSIZE={PD_FLOATSIZE}"))
-        .clang_arg("-DPD_INTERNAL=0") // Undefine PD_INTERNAL because it is not needed for bindings and cmake complains about it.
+        .clang_arg("-DPD_INTERNAL=1")
         .clang_arg("-std=c11")
         // Tell cargo to invalidate the built crate whenever any of the
         // included header files changed.