globals aren't working

Question

>>> t('$x')()
Traceback (most recent call last):
    ...
NameError: global name 'x' is not defined
>>> t('$x', globals={'x': 1})()

I expected:

u'1\n'

the actual was:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 't' is not defined

Why aren't my globals working?