Tech issue 100720: Resolved

Graphviz now successfully works on my Snow Leopard installation.

The root cause: Turns out that some of my earlier MacPorts ports were outdated since they were built when I was still running Mac OS X Leopard. Installing the graphviz-gui port would appear to be fine, however, since some of the Graphviz dependencies were outdated for Mac OS X Snow Leopard’s 64-bit architecture, running the graphviz-gui port would fail.

The fix: By re-installing the graphviz-gui port after wiping out all the installed MacPorts ports (and therefore starting from a “clean” starting point), all of the Graphviz dependencies were re-installed correctly to work with Snow Leopard’s 64-bit architecture.

Command-line history:

sudo port -f uninstall installed
sudo port install graphviz-gui
dot -Tpng /tmp/diagram.txt > /tmp/test.png