cffi-0.8.6 -> 0.9.2 upgrade causes verifier module to stop pygit2 from operating #534

/usr/lib64/python3.3/site-packages/pygit2/errors.py in <module>()
     27 
     28 # ffi
---> 29 from .ffi import ffi, C
     30 
     31 from _pygit2 import GitError

/usr/lib64/python3.3/site-packages/pygit2/ffi.py in <module>()
     33 
     34 
---> 35 ffi, C = get_ffi()

/usr/lib64/python3.3/site-packages/pygit2/_utils.py in get_ffi()
     99     libgit2_bin, libgit2_include, libgit2_lib = get_libgit2_paths()
    100     C = ffi.verify(preamble, modulename=modulename, libraries=["git2"],
--> 101                    include_dirs=[libgit2_include], library_dirs=[libgit2_lib])
    102 
    103     # Ok

/usr/lib64/python3.3/site-packages/cffi/api.py in verify(self, source, tmpdir, **kwargs)
    365         # Make a Verifier() and use it to load the library.
    366         self.verifier = Verifier(self, source, tmpdir, **kwargs)
--> 367         lib = self.verifier.load_library()
    368         #
    369         # Save the loaded library for keep-alive purposes, even

/usr/lib64/python3.3/site-packages/cffi/verifier.py in load_library(self)
     93                 if not self._has_module:
     94                     if not self._has_source:
---> 95                         self._write_source()
     96                     self._compile_module()
     97             return self._load_library()

/usr/lib64/python3.3/site-packages/cffi/verifier.py in _write_source(self, file)
    181             if needs_written:
    182                 _ensure_dir(self.sourcefilename)
--> 183                 with open(self.sourcefilename, "w") as fp:
    184                     fp.write(source_data)
    185 

PermissionError: [Errno 13] Permission denied: '/usr/lib64/python3.3/site-packages/pygit2/__pycache__/pygit2_cffi_64b6b464x5470904.c'