diff -urNp -x '*.orig' cmake-3.17.2.org/Modules/FindRuby.cmake cmake-3.17.2/Modules/FindRuby.cmake
--- cmake-3.17.2.org/Modules/FindRuby.cmake	2021-04-12 22:19:23.761018307 +0200
+++ cmake-3.17.2/Modules/FindRuby.cmake	2021-04-12 22:19:24.521040438 +0200
@@ -207,6 +207,7 @@ if( "${Ruby_FIND_VERSION_SHORT_NODOT}" G
   find_path(Ruby_CONFIG_INCLUDE_DIR
     NAMES ruby/config.h  config.h
     HINTS
+      ${Ruby_HDR_DIR}
       ${Ruby_HDR_DIR}/${Ruby_ARCH}
       ${Ruby_ARCH_DIR}
       ${Ruby_ARCHHDR_DIR}