az aks list - No module named '_cffi_backend'

[spboyer]

Command Ran: az aks list

Fixed issue with brew link --overwrite python3

Environment summary

Install Method: pip & homebrew
CLI Version: azure-cli (2.0.21)

Python location '/usr/local/opt/python3/bin/python3.6'
Extensions directory '/Users/shayneboyer/.azure/cliextensions'

Python (Darwin) 3.6.3 (default, Nov  1 2017, 11:10:52)
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.38)]

Error:

No module named '_cffi_backend'
Traceback (most recent call last):
  File "/usr/local/Cellar/azure-cli/2.0.21/libexec/lib/python3.6/site-packages/azure/cli/main.py", line 36, in main
    cmd_result = APPLICATION.execute(args)
  File "/usr/local/Cellar/azure-cli/2.0.21/libexec/lib/python3.6/site-packages/azure/cli/core/application.py", line 177, in execute
    self.configuration.load_params(command)
  File "/usr/local/Cellar/azure-cli/2.0.21/libexec/lib/python3.6/site-packages/azure/cli/core/application.py", line 50, in load_params
    commands.load_params(command)
  File "/usr/local/Cellar/azure-cli/2.0.21/libexec/lib/python3.6/site-packages/azure/cli/core/commands/__init__.py", line 391, in load_params
    command_table[command].load_arguments()
  File "/usr/local/Cellar/azure-cli/2.0.21/libexec/lib/python3.6/site-packages/azure/cli/core/commands/__init__.py", line 335, in load_arguments
    self.arguments.update(self.arguments_loader())
  File "/usr/local/Cellar/azure-cli/2.0.21/libexec/lib/python3.6/site-packages/azure/cli/core/commands/__init__.py", line 647, in arguments_loader
    return extract_args_from_signature(get_op_handler(operation), no_wait_param=no_wait_param)
  File "/usr/local/Cellar/azure-cli/2.0.21/libexec/lib/python3.6/site-packages/azure/cli/core/commands/__init__.py", line 537, in get_op_handler
    op = import_module(mod_to_import)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 665, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "/usr/local/Cellar/azure-cli/2.0.21/libexec/lib/python3.6/site-packages/azure/cli/command_modules/acs/custom.py", line 37, in <module>
    from azure.cli.command_modules.acs import acs_client, proxy
  File "/usr/local/Cellar/azure-cli/2.0.21/libexec/lib/python3.6/site-packages/azure/cli/command_modules/acs/acs_client.py", line 12, in <module>
    import paramiko
  File "/usr/local/Cellar/azure-cli/2.0.21/libexec/lib/python3.6/site-packages/paramiko/__init__.py", line 31, in <module>
    from paramiko.transport import SecurityOptions, Transport
  File "/usr/local/Cellar/azure-cli/2.0.21/libexec/lib/python3.6/site-packages/paramiko/transport.py", line 57, in <module>
    from paramiko.ed25519key import Ed25519Key
  File "/usr/local/Cellar/azure-cli/2.0.21/libexec/lib/python3.6/site-packages/paramiko/ed25519key.py", line 17, in <module>
    import bcrypt
  File "/usr/local/Cellar/azure-cli/2.0.21/libexec/lib/python3.6/site-packages/bcrypt/__init__.py", line 25, in <module>
    from bcrypt import _bcrypt
ImportError: No module named '_cffi_backend'

[skyhit]

I got the same problem in macOS

[julienstroheker]

Did you try brew link --overwrite python3 ?

[benofben]

This fixed it for me --- brew link --overwrite python3 I also had an old az hiding in my path that was painful to hunt down.

[qiangli]

Cool! brew link --overwrite python3 fixed same issue for azure-cli (2.0.33) on
System Version: OS X 10.11.6 (15G1217) Kernel Version: Darwin 15.6.0

[shershen08]

Having the same problem!

Tried:

$: brew link --overwrite python3
Warning: Already linked: /usr/local/Cellar/python/3.7.0
To relink: brew unlink python && brew link python
$: brew unlink python
$: brew link --overwrite python3

$: az aks browse
No module named '_cffi_backend'
Traceback (most recent call last):
  File "/usr/local/Cellar/azure-cli/2.0.38/libexec/lib/python3.6/site-packages/knack/cli.py", line 197, in invoke
    cmd_result = self.invocation.e

Didn't solve an issue for me.

[kventil]

Same here.

△ ~ az --version
azure-cli (2.0.38)

 ▲ ~ python3 --version
Python 3.7.0

Update:
python3 -m pip install cffi fixed it for me.

[frli]

Thanks @kventil, that fixed it for me as well.

[shershen08]

@kventil Thanks!

[brichins]

@kventil - Your workaround worked like a charm for me. Thank you for posting.

[twitchax]

@mboersma for FYI.

[kgopi05]

@kventil Thanks! it works for me ..

[mboersma]

@tjprescott this was a quirk of Homebrew packaging and the workaround shouldn't be necessary any longer. I think this can be closed.

[shuchow]

FYI, I was still having this issue with Homebrew 1.9.3 (2/2/2019 commit) and azure-cli version 2.0.57. Had to use "brew link --overwrite python3" to solve the issue.