Clifford Wolf:

package/tschmidt/graphviz/graphviz.conf

@@ -0,0 +1,4 @@
+
+# for gvconfig_hotfix.patch
+export ROCK_BUILDING_GRAPHVIZ=1
+

package/tschmidt/graphviz/gvconfig_hotfix.patch

@@ -19,16 +19,17 @@
 
 --- ./lib/gvc/gvconfig.c.orig	2005-08-18 11:25:03.000000000 +0200
 +++ ./lib/gvc/gvconfig.c	2005-08-18 11:28:17.000000000 +0200
-@@ -235,7 +235,11 @@
+@@ -235,7 +235,12 @@
      gvplugin_library_t *library;
      char *plugin_glob = "libgvplugin*.so.?";
  
 -    if (config_path) {
 +    // this so-called "config file" should be in /var/cache, morrons!
-+    // I'm going to change the config file location, so here is a little
-+    // hack which skips updating the file when graphviz is called in a
-+    // Build-Pkg process tree... - clifford
-+    if (config_path && !getenv("ROCKCFG_ID")) {
++    // here is a little hack which skips updating the file when graphviz is
++    // called in a Build-Pkg process tree (unless when building graphviz).
++    // The variable ROCK_BUILDING_GRAPHVIZ must be set by the graphviz.conf
++    // script when building graphviz.  - clifford
++    if (config_path && (!getenv("ROCKCFG_ID") || getenv("ROCK_BUILDING_GRAPHVIZ"))) {
  	f = fopen(config_path,"w");
  	if (!f) {
  	    agerr(AGERR,"failed to open %s for write.\n", config_path);