The variable, not the literal. Thanks mjmac.

diff --git a/build/lbuild b/build/lbuild
index c767327..2f8b79f 100755 (executable)
--- a/build/lbuild
+++ b/build/lbuild
@@ -742,7 +742,7 @@ EOF
                 fatal 1 "$LINUX does not exist!  Install a kernel-devel package!"
             fi
         fi
-        CONFIGURE_FLAGS="CONFIGURE_FLAGS --disable-server"
+        CONFIGURE_FLAGS="$CONFIGURE_FLAGS --disable-server"
         build_lustre
     fi
 else