Segmentation fault for a node with rank=sink that is not connected to other nodes
When there is a node with rank=sink and some others with different ranks (rank=same in my instance), then this "sink-node" have to be connected to any of "not-sink-nodes", otherwise graphviz fails with Segmentation Fault. Additionally, if there are several "sink-nodes", only one of them has to be connected to "non-sink" nodes. I attached two files as examples.
Environment: dot - graphviz version 2.40.1 (20161225.0304), Fedora 27