cmake: better error message

diff --git a/tools/cmake/Modules/FindGraphviz.cmake b/tools/cmake/Modules/FindGraphviz.cmake
index 5e80fa4..25aa03f 100644 (file)
--- a/tools/cmake/Modules/FindGraphviz.cmake
+++ b/tools/cmake/Modules/FindGraphviz.cmake
@@ -39,5 +39,5 @@ message(STATUS "Looking for graphviz")
 if(HAVE_GRAPHVIZ)
   message(STATUS "Looking for graphviz - found")
 else()
-  message(STATUS "Looking for graphviz - not found")
+  message(STATUS "Looking for graphviz - not found (try installing libgraphviz-dev)")
 endif()