I ran hcustom SOP_Star.C and get this error –

g++: Command not found.
Making SOP_Star.o and /Users/robertbennett/Library/Preferences/houdini/11.0/dso/SOP_Star.dylib from SOP_Star.C
sh: g++: command not found
Compile failed

I can run hdk with apprentice right?

Do you have Xcode installed? It is attempting to compile the file but cannot find the compiler program.

I now have xcode 2.2.1 and now I get this error –

Making SOP_Star.o and /Users/robertbennett/Library/Preferences/houdini/11.0/dso/SOP_Star.dylib from SOP_Star.C
g++: Unable to guess config name for arch x86_64
Compile failed

So I'm now running on OS 10.6.8 and just installed xcode 3.2.6.
I run – hcustom toolkit/samples/SOP/SOP_Star.C
and I get this new error –

Making toolkit/samples/SOP/SOP_Star.o and /Users/robertbennett/Library/Preferences/houdini/11.0/dso/SOP_Star.dylib from toolkit/samples/SOP/SOP_Star.C
/var/folders/m3/m3sGa6VlEzmc0V-wWp+1N++++TI/-Tmp-//cczFe1R6.s:unknown:FATAL:can't create output file: toolkit/samples/SOP/SOP_Star.o
Compile failed

Copy SOP_Star.C to your HOME directory and run hcustom on it from there.