Error on more than 128 cluster subgraphs
Steps to reproduce
Seems to happen with every Graphviz build. Can be reliably reproduced with GraphvizOnline.
Error: trouble in init_rank f127 1 Error: in routesplines, cannot find NORMAL edge Process 4649 exited with status = 1 (0x00000001)
macOS Big Sur
Installed via Homebrew.
dot - graphviz version 2.47.1 (20210417.1919)
Error: trouble in init_rank has come up in some other bug reports such as #1939, but this looks different to me. The conditions are much simpler. Any graph with 128 or more cluster subgraphs which each contain 1 (or more)
rank=source node and one (or more) free node.
rank=sink is equally problematic. Edges aren't needed to reproduce.
In the provided example, comment out any node or cluster and the issue goes away.