I get a kernel panic in Mac OSX Mavericks (10.9.4) running this
import frida p = frida.attach("cat") print(p.enumerate_modules())
Not sure if this is a similar problem or not but doing print([x.name for x in p.enumerate_modules()]) instead works just fine.
Edit: Looks like the problem may be attaching to a program a second time. Not sure if I need to run some detach command or whatnot.