macOS M1: failure to find X11
Following on from #2411 (closed) and #2422 (closed), the Autotools build system fails to find X11 libraries on an M1 mac. You can see the results here: https://gitlab.com/graphviz/graphviz/-/jobs/4495371798. You can also see the X11 libraries being installed, so something in the detection is clearly wrong.
The result of this is that vimdot does not get built and the existence check of it later fails.