We have some downstream patches and other scripts that include variables to
be expanded by cmake. Cmake needs to know about them, so adding them manually.

 # Install libgcc as  mylibgcc.a
--- mariadb-10.5.5/scripts/CMakeLists.txt.old	2020-09-24 10:13:35.272589689 +0200
+++ mariadb-10.5.5/scripts/CMakeLists.txt	2020-09-24 10:17:31.428985798 +0200
@@ -377,6 +377,34 @@
       INSTALL_LINK(${file} ${binname} ${INSTALL_BINDIR} ${${file}_COMPONENT})
     ENDIF()
   ENDFOREACH()
+
+  # files for systemd
+  SET(SYSTEMD_SCRIPTS
+    mariadb.tmpfiles.d
+    mysql.service
+    mysql@.service
+    mariadb-prepare-db-dir
+    mariadb-check-socket
+    mariadb-check-upgrade
+    mariadb-scripts-common
+    mysql_config_multilib
+    clustercheck
+    galera_new_cluster
+    my.cnf
+  )
+  FOREACH(file ${SYSTEMD_SCRIPTS})
+    IF(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${file}.sh)
+      CONFIGURE_FILE(${CMAKE_CURRENT_SOURCE_DIR}/${file}.sh
+        ${CMAKE_CURRENT_BINARY_DIR}/${file} ESCAPE_QUOTES @ONLY)
+    ELSEIF(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${file}.in)
+      CONFIGURE_FILE(${CMAKE_CURRENT_SOURCE_DIR}/${file}.in
+        ${CMAKE_CURRENT_BINARY_DIR}/${file} ESCAPE_QUOTES @ONLY)
+    ELSE()
+      MESSAGE(FATAL_ERROR "Can not find ${file}.sh or ${file}.in in "
+        "${CMAKE_CURRENT_SOURCE_DIR}" )
+    ENDIF()
+  ENDFOREACH()
+
 ENDIF()
 
 # Install libgcc as  mylibgcc.a