improve error message in the case of dot not finding dot_layout plugin

diff --git a/lib/common/input.c b/lib/common/input.c
index 34fe1e4032d17de84c4753fdb5933e0100d8f0cf..e669a711b9a400f33da47b16e5d3c1dd868fbf7f 100644 (file)
--- a/lib/common/input.c
+++ b/lib/common/input.c
@@ -261,6 +261,9 @@ void dotneato_args_initialize(GVC_t * gvc, int argc, char **argv)
     i = gvlayout_select(gvc, gvc->common.cmdname);
     if (i == NO_SUPPORT) {
        fprintf(stderr, "There is no layout engine support for \"%s\"\n", gvc->common.cmdname);
+        if (streq(gvc->common.cmdname, "dot")) {
+          fprintf(stderr, "Perhaps \"dot -c\" needs to be run by root to register the plugins?\n");
+       }
        exit(1);
     }