@@ -269,11 +269,13 @@ disable(){

 }

 enabled(){

-    eval test "x\$$1" = "xyes"

+    test "${1#!}" = "$1" && op== || op=!=

+    eval test "x\$${1#!}" $op "xyes"

 }

 disabled(){

-    eval test "x\$$1" = "xno"

+    test "${1#!}" = "$1" && op== || op=!=

+    eval test "x\$${1#!}" $op "xno"

 }

 enabled_all(){

@@ -317,6 +319,7 @@ is_in(){

 check_deps(){

     for cfg; do

+        cfg="${cfg#!}"

         enabled ${cfg}_checking && die "Circular dependency for $cfg."

         disabled ${cfg}_checking && continue

         enable ${cfg}_checking