I'm using OSX 10.6.8. I am trying to install NetworkX, which is supposed to be able to read dot files, manipulate the graph, and write out graphs to file (including in dot & other formats). NetworkX requires pygraphviz to handle dot files, which in turn requires Graphviz. I have Graphviz (2.34) installed, but pygraphviz still says:
2) Your Graphviz package might incomplete.
Install the binary development subpackage (e.g. libgraphviz-dev or similar.)

I don't know what "subpackage" they are talking about. Any suggestions?

For some systems, the

For some systems, the binaries are split into a basic package and a development package, which contains functions for those applications that use the software intensively. For example, if you go to, you'll see packages with "dev" or "devel" in the name. For OSX, you need to check where you got the package. I think the package we provide contains everything, but macports has both a graphviz and a graphviz-devel packages.

Well, I originally got

Well, I originally got Graphviz from the download section here, but couldn't find libgraphviz-dev anywhere on my system.  'port install py27-pygraphviz' installed graphviz-2.36 as a dependency.  And now when I try 'sudo port install graphviz-devel', it complains that:
Error: Unable to execute port: Can't install graphviz-devel because conflicting ports are installed: graphviz

Indeed, the graphviz and

Indeed, the graphviz and graphviz-devel ports conflict, so you need to uninstall one to install the other.

However, I have downloaded pygraphviz and think the answer is simpler. If you installed graphviz from here, by default the files are placed under /usr/local. The problem in the pygraphviz script is that it is trying pkg-config to find out where graphviz is, and is failing. One way to fix this is to set PKG_CONFIG_PATH=/usr/local/lib/pkgconfig, and then rerun python install. Or you can just edit the file and remove the comments  from the lines under OSX, Linus, alternate locations:

# OSX, Linux, alternate location

If you want to use the macports version of graphviz, uncomment the two lines under # OSX (MacPorts).

These worked for me.