diff -up rpm-4.18.1/macros.in.orig rpm-4.18.1/macros.in
--- rpm-4.18.1/macros.in.orig	2023-03-15 13:52:55.211928040 +0100
+++ rpm-4.18.1/macros.in	2023-03-15 13:55:04.113129930 +0100
@@ -746,7 +746,9 @@ package or when debugging this package.\
   %{?_javaclasspath:CLASSPATH=\"%{_javaclasspath}\"\
   export CLASSPATH}\
   PKG_CONFIG_PATH=\"${PKG_CONFIG_PATH}:%{_libdir}/pkgconfig:%{_datadir}/pkgconfig\"\
-  export PKG_CONFIG_PATH
+  export PKG_CONFIG_PATH\
+  CONFIG_SITE=${CONFIG_SITE:-NONE}\
+  export CONFIG_SITE
 
 %___build_pre	\
   %{___build_pre_env} \