[Python-modules-team] Bug#882069: python3-keyring: ModuleNotFoundError: No module named '_cffi_backend'

[Rémi Letot]

Package: python3-keyring
Version: 10.4.0-1
Severity: normal

Dear Maintainer,

I'm using python3-keyring in scripts to get my mail password from
gnome-keyring. It has worked fine for ages, but suddenly I get this:

hobbes at sphax:~$ python3 -m keyring get SERVICE USER
Traceback (most recent call last):
  File "/usr/lib/python3.6/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "/usr/lib/python3.6/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/usr/lib/python3/dist-packages/keyring/__main__.py", line 3, in <module>
    cli.main()
  File "/usr/lib/python3/dist-packages/keyring/cli.py", line 101, in main
    return cli.run(argv)
  File "/usr/lib/python3/dist-packages/keyring/cli.py", line 54, in run
    password = get_password(service, username)
  File "/usr/lib/python3/dist-packages/keyring/core.py", line 41, in get_password
    return _keyring_backend.get_password(service_name, username)
  File "/usr/lib/python3/dist-packages/keyring/backends/SecretService.py", line 65, in get_password
    return item.get_secret().decode('utf-8')
  File "/usr/lib/python3/dist-packages/secretstorage/item.py", line 102, in get_secret
    decryptor = Cipher(aes, modes.CBC(aes_iv), default_backend()).decryptor()
  File "/usr/lib/python3/dist-packages/cryptography/hazmat/backends/__init__.py", line 15, in default_backend
    from cryptography.hazmat.backends.openssl.backend import backend
  File "/usr/lib/python3/dist-packages/cryptography/hazmat/backends/openssl/__init__.py", line 7, in <module>
    from cryptography.hazmat.backends.openssl.backend import backend
  File "/usr/lib/python3/dist-packages/cryptography/hazmat/backends/openssl/backend.py", line 16, in <module>
    from cryptography import utils, x509
  File "/usr/lib/python3/dist-packages/cryptography/x509/__init__.py", line 8, in <module>
    from cryptography.x509.base import (
  File "/usr/lib/python3/dist-packages/cryptography/x509/base.py", line 16, in <module>
    from cryptography.x509.extensions import Extension, ExtensionType
  File "/usr/lib/python3/dist-packages/cryptography/x509/extensions.py", line 18, in <module>
    from cryptography.hazmat.primitives import constant_time, serialization
  File "/usr/lib/python3/dist-packages/cryptography/hazmat/primitives/constant_time.py", line 9, in <module>
    from cryptography.hazmat.bindings._constant_time import lib
ModuleNotFoundError: No module named '_cffi_backend'


It does not barfs if SERVICE or USER is wrong, only when the combination
is good.

Do you need any other information ?

Thanks for your work,
--
Rémi

-- System Information:
Debian Release: buster/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.13.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=fr_FR.utf8, LC_CTYPE=fr_FR.utf8 (charmap=UTF-8), LANGUAGE=fr_FR.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages python3-keyring depends on:
ii  python3                3.6.3-2
ii  python3-dbus           1.2.4-1+b4
ii  python3-secretstorage  2.3.1-2

Versions of packages python3-keyring recommends:
ii  python3-keyrings.alt  2.2-2

Versions of packages python3-keyring suggests:
ii  gnome-keyring     3.20.1-1
pn  libkf5wallet-bin  <none>

-- no debconf information