Build on Mac OS X

cffi fails to build on OS X ({{{CFLAGS=-I/usr/include/ffi python setup.py build}}} on my system), with the error:

{{{ c/_ffi_backend.c:131: error: thread-local storage not supported for this target }}}

{{{__thread}}} appears to be the problem; it is less well-supported (if at all?) on OS X?

Thanks! Should be fixed (rev 3fb35a967ec1). Can you try again?

Works! Thanks for the quick fix.