gernerate a "user friendly" error message instead of assert failure.

diff --git a/lib/common/input.c b/lib/common/input.c
index 402648332f5f4934295f634cb8b1c5f89c80ed21..f9fd773701bf43fd708ead2781d024231ee75fc3 100644 (file)
--- a/lib/common/input.c
+++ b/lib/common/input.c
@@ -401,7 +401,12 @@ void dotneato_args_initialize(GVC_t * gvc, int argc, char **argv)
     /* if no -Txxx, then set default format */
     if (!gvc->jobs || !gvc->jobs->output_langname) {
        v = gvjobs_output_langname(gvc, "dot");
-       assert(v);  /* "dot" should always be available as an output format */
+       if (!v) {
+//     assert(v);  /* "dot" should always be available as an output format */
+               fprintf(stderr,
+                       "Unable to find even the default \"-Tdot\" renderer.  Has the config\nfile been generated by running \"dot -c\" with installer's priviledges?\n");
+                       exit(1);
+       }
     }
 
     /* set persistent attributes here (if not already set from command line options) */