用pipenv install 的时候一直报下面的错误：

Installing initially failed dependencies…
InstallError: File “/usr/local/Cellar/pipenv/2020.11.15/libexec/lib/python3.9/site-packages/pipenv/cli/command.py”, line 233, in install
InstallError: retcode = do_install(
InstallError: File “/usr/local/Cellar/pipenv/2020.11.15/libexec/lib/python3.9/site-packages/pipenv/core.py”, line 2052, in do_install
InstallError: File “/usr/local/Cellar/pipenv/2020.11.15/libexec/lib/python3.9/site-packages/pipenv/core.py”, line 1304, in do_init
InstallError: File “/usr/local/Cellar/pipenv/2020.11.15/libexec/lib/python3.9/site-packages/pipenv/core.py”, line 899, in do_install_dependencies
InstallError: File “/usr/local/Cellar/pipenv/2020.11.15/libexec/lib/python3.9/site-packages/pipenv/core.py”, line 796, in batch_install
InstallError: File “/usr/local/Cellar/pipenv/2020.11.15/libexec/lib/python3.9/site-packages/pipenv/core.py”, line 703, in _cleanup_procs
InstallError: raise exceptions.InstallError(c.dep.name, extra=err_lines)
[pipenv.exceptions.InstallError]: Looking in indexes: https://mirrors.aliyun.com/pypi/simple/
[pipenv.exceptions.InstallError]: Collecting cryptography==3.4.7
[pipenv.exceptions.InstallError]: Using cached https://mirrors.aliyun.com/pypi/packages/9b/77/461087a514d2e8ece1c975d8216bc03f7048e6090c5166bc34115afdaa53/cryptography-3.4.7.tar.gz (546 kB)
[pipenv.exceptions.InstallError]: ERROR: Disabling PEP 517 processing is invalid: project specifies a build backend of setuptools.build_meta in pyproject.toml
ERROR: Couldn’t install package: cryptography

尝试了半天，解决方案是：

brew install rust

晕死~！

参考链接：

https://github.com/pyca/cryptography/issues/5773