Python3 Ctypes Backend Version Mismatch on Ubuntu 16.04

I want pysoundfile to work correctly on Python3 so badly, but for the life of me I can’t figure out a workaround for this.

In [1]: import soundfile
---------------------------------------------------------------------------
AssertionError                            Traceback (most recent call last)
<ipython-input-1-aaba2ade8dee> in <module>()
----> 1 import soundfile

/usr/local/lib/python3.5/dist-packages/soundfile.py in <module>()
     21     _unicode = str
     22 
---> 23 _ffi = _FFI()
     24 _ffi.cdef("""
     25 enum

/usr/local/lib/python3.5/dist-packages/cffi/api.py in __init__(self, backend)
     57             from . import __version__
     58             assert backend.__version__ == __version__, \
---> 59                "version mismatch, %s != %s" % (backend.__version__, __version__)
     60             # (If you insist you can also try to pass the option
     61             # 'backend=backend_ctypes.CTypesBackend()', but don't

AssertionError: version mismatch, 1.5.2 != 1.9.1

My cffi.__version__ is '1.9.1', and I have no idea how to change the backend. This may not strictly be a pysoundfile issue, but this is the only place where I encounter this problem and I’ve given up trying to fix it so many times…

[Teque5]

@mgeier this fixed it.

I guess at some point I used pip to upgrade cffi. Removing it via pip and installing it via apt-get install python3-cffi seemed to fix the problem on Ubuntu 16.04.

Thanks. Maybe this will help someone else.

[mgeier]

@Teque5 You should probably not remove python3-cffi-backend if other needed packages depend on it.

You should try to remove the version of the cffi module which you previously installed with pip, and just use the one coming with Ubuntu.

Run this multiple times, until it says there is no package with that name (or that it won’t uninstall the one in /usr/lib/python3/dist-packages/):

python3 -m pip uninstall cffi

If it still doesn’t work, have a look if the directory /usr/local/lib/python3.5/dist-packages/cffi/ still exists and manually delete it.