abs_top_builddir="@abs_top_builddir@"
prefix=${prefix-@prefix@}
-MES_PREFIX=${srcdest}mes
+MES_PREFIX=${MES_PREFIX-${srcdest}mes}
export MES_PREFIX
GUILE_LOAD_COMPILED_PATH="$abs_top_builddir/module${GUILE_LOAD_COMPILED_PATH:+:}$GUILE_LOAD_COMPILED_PATH"