libvaladoc: Improve error message on failing to load a driver

https://bugzilla.gnome.org/show_bug.cgi?id=711559

diff --git a/src/libvaladoc/moduleloader.vala b/src/libvaladoc/moduleloader.vala
index 06e6fe1bf1e63bf1eccbfd8c24c25349575d1681..b7bcae6aa0a5e4699e8f728e9a90fe6fdfb3ca96 100644 (file)
--- a/src/libvaladoc/moduleloader.vala
+++ b/src/libvaladoc/moduleloader.vala
@@ -174,7 +174,10 @@ public class Valadoc.ModuleLoader : Object {
                }
 
 
-               reporter.simple_error (null, "No suitable driver found.");
+               reporter.simple_error (null, "No suitable driver found for libvala version " +
+                                                          "%" + int64.FORMAT_MODIFIER + "d.%" + int64.FORMAT_MODIFIER + "d.%" + int64.FORMAT_MODIFIER + "d. " +
+                                      "Ensure the selected vala version was installed while building valadoc or use --driver to select another one.",
+                                                          segment_a, segment_b, segment_c);
                return null;
        }