conversion type not yet supported: c

import datetime
now = datetime.datetime.now()
now2 = datetime.datetime.now()
print now2-now

// Output: 0:00:00.000198

import datetime
now = datetime.datetime.now()
print now

[u@x220 grumpy]$ grumpc -modname=hello $GOPATH/src/__python__/hello.py >     $GOPATH/src/__python__/hello/module.go
[u@x220 grumpy]$ echo 'import hello' | grumprun
NotImplementedError: conversion type not yet supported: c