ImportError: Symbol not found: _ffi_prep_closure on Apple Silicon with CPython 3.9.6

System: macOS Big Sur 11.5 (Apple Silicon)

Python: CPython 3.9.6 installed by pyenv. (Configure flags: --with-dtrace --with-framework --enable-optimizations --with-ensurepip=upgrade)

CFFI VERSION: 1.14.6

Package Management:

poetry 1.1.7  
pip 21.2.2
setuptools 57.0.0

Steps

pip install bcrypt

Expect

Installation success.

Actual

$ python -VV
Python 3.9.6 (default, Jul 12 2021, 18:23:45)
[Clang 12.0.5 (clang-1205.0.22.9)]

$ pip install bcrypt -U                                                                            
Collecting bcrypt
  Using cached bcrypt-3.2.0.tar.gz (42 kB)
  Installing build dependencies ... done
  Getting requirements to build wheel ... done
    Preparing wheel metadata ... error
    ERROR: Command errored out with exit status 1:
     command: /Users/User/Library/Caches/pypoetry/virtualenvs/athena-KNwCPsJq-py3.9/bin/python /Users/User/Library/Caches/pypoetry/virtualenvs/athena-KNwCPsJq-py3.9/lib/python3.9/site-packages/pip/_vendor/pep517/in_process/_in_process.py prepare_metadata_for_build_wheel /var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/tmp74wwwf_q
         cwd: /private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-install-azxktwnp/bcrypt_892886653fab43e190fa3b13d0dcd69b
    Complete output (39 lines):
    Traceback (most recent call last):
      File "/Users/User/Library/Caches/pypoetry/virtualenvs/athena-KNwCPsJq-py3.9/lib/python3.9/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 349, in <module>
        main()
      File "/Users/User/Library/Caches/pypoetry/virtualenvs/athena-KNwCPsJq-py3.9/lib/python3.9/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 331, in main
        json_out['return_val'] = hook(**hook_input['kwargs'])
      File "/Users/User/Library/Caches/pypoetry/virtualenvs/athena-KNwCPsJq-py3.9/lib/python3.9/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 151, in prepare_metadata_for_build_wheel
        return hook(metadata_directory, config_settings)
      File "/private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-build-env-ka92635y/overlay/lib/python3.9/site-packages/setuptools/build_meta.py", line 166, in prepare_metadata_for_build_wheel
        self.run_setup()
      File "/private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-build-env-ka92635y/overlay/lib/python3.9/site-packages/setuptools/build_meta.py", line 150, in run_setup
        exec(compile(code, __file__, 'exec'), locals())
      File "setup.py", line 46, in <module>
        setup(
      File "/private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-build-env-ka92635y/overlay/lib/python3.9/site-packages/setuptools/__init__.py", line 153, in setup
        return distutils.core.setup(**attrs)
      File "/Users/User/.pyenv/versions/3.9.6/lib/python3.9/distutils/core.py", line 108, in setup
        _setup_distribution = dist = klass(attrs)
      File "/private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-build-env-ka92635y/overlay/lib/python3.9/site-packages/setuptools/dist.py", line 455, in __init__
        _Distribution.__init__(self, {
      File "/Users/User/.pyenv/versions/3.9.6/lib/python3.9/distutils/dist.py", line 292, in __init__
        self.finalize_options()
      File "/private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-build-env-ka92635y/overlay/lib/python3.9/site-packages/setuptools/dist.py", line 807, in finalize_options
        ep(self)
      File "/private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-build-env-ka92635y/overlay/lib/python3.9/site-packages/setuptools/dist.py", line 814, in _finalize_setup_keywords
        ep.load()(self, ep.name, value)
      File "/private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-build-env-ka92635y/overlay/lib/python3.9/site-packages/cffi/setuptools_ext.py", line 219, in cffi_modules
        add_cffi_module(dist, cffi_module)
      File "/private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-build-env-ka92635y/overlay/lib/python3.9/site-packages/cffi/setuptools_ext.py", line 49, in add_cffi_module
        execfile(build_file_name, mod_vars)
      File "/private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-build-env-ka92635y/overlay/lib/python3.9/site-packages/cffi/setuptools_ext.py", line 25, in execfile
        exec(code, glob, glob)
      File "src/build_bcrypt.py", line 21, in <module>
        ffi = FFI()
      File "/private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-build-env-ka92635y/overlay/lib/python3.9/site-packages/cffi/api.py", line 48, in __init__
        import _cffi_backend as backend
    ImportError: dlopen(/private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-build-env-ka92635y/overlay/lib/python3.9/site-packages/_cffi_backend.cpython-39-darwin.so, 2): Symbol not found: _ffi_prep_closure
      Referenced from: /private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-build-env-ka92635y/overlay/lib/python3.9/site-packages/_cffi_backend.cpython-39-darwin.so
      Expected in: flat namespace
     in /private/var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/pip-build-env-ka92635y/overlay/lib/python3.9/site-packages/_cffi_backend.cpython-39-darwin.so
    ----------------------------------------
WARNING: Discarding https://files.pythonhosted.org/packages/d8/ba/21c475ead997ee21502d30f76fd93ad8d5858d19a3fad7cd153de698c4dd/bcrypt-3.2.0.tar.gz#sha256=5b93c1726e50a93a033c36e5ca7fdcd29a5c7395af50a6892f5d9e7c6cfbfb29 (from https://pypi.org/simple/bcrypt/) (requires-python:>=3.6). Command errored out with exit status 1: /Users/User/Library/Caches/pypoetry/virtualenvs/athena-KNwCPsJq-py3.9/bin/python /Users/User/Library/Caches/pypoetry/virtualenvs/athena-KNwCPsJq-py3.9/lib/python3.9/site-packages/pip/_vendor/pep517/in_process/_in_process.py prepare_metadata_for_build_wheel /var/folders/5s/8rczg1gs4wb59y9s22nc3f_r0000gn/T/tmp74wwwf_q Check the logs for full command output.