I’ve made some progress: I can get a stub program to work under Visual Studio, but fails when compiled with Qt 5.13. (See 'gvLayout' crashing - #2 by sprezzatura). I can escape having to compile Graphviz for the time being.
Click for project file & source: Visual Studio project or Qt project.
Are there any Graphviz DLLs that I need to add to my executable directory? I’ve added them all, and it doesn’t seem to make a difference.