在 OS X 上使用 pip 安装 bcrypt 时出错：找不到 ffi.h（已安装 libffi）

Question

我在尝试使用 pip 安装 bcrypt 时遇到此错误。我在几个地方（Xcode OS X SDK 和自制软件）安装了 libffi，但我不知道如何告诉 pip 去寻找它。有什么建议吗？

Downloading/unpacking bcrypt==1.0.2 (from -r requirements.txt (line 41))
  Running setup.py egg_info for package bcrypt
    OS/X: confusion between 'cc' versus 'gcc' (see issue 123)
    will not use '__thread' in the C code
    c/_cffi_backend.c:14:10: fatal error: 'ffi.h' file not found
    #include <ffi.h>
             ^
    1 error generated.
    Traceback (most recent call last):
      File "<string>", line 16, in <module>
      File "/Users/cody/virtualenvs/analytics/build/bcrypt/setup.py", line 104, in <module>
        "Programming Language :: Python :: 3.3",
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/core.py", line 112, in setup
        _setup_distribution = dist = klass(attrs)
      File "build/bdist.macosx-10.9-intel/egg/setuptools/dist.py", line 239, in __init__
      File "build/bdist.macosx-10.9-intel/egg/setuptools/dist.py", line 264, in fetch_build_eggs
      File "build/bdist.macosx-10.9-intel/egg/pkg_resources.py", line 620, in resolve
        dist = best[req.key] = env.best_match(req, ws, installer)
      File "build/bdist.macosx-10.9-intel/egg/pkg_resources.py", line 858, in best_match
        return self.obtain(req, installer) # try and download/install
      File "build/bdist.macosx-10.9-intel/egg/pkg_resources.py", line 870, in obtain
        return installer(requirement)
      File "build/bdist.macosx-10.9-intel/egg/setuptools/dist.py", line 314, in fetch_build_egg
      File "build/bdist.macosx-10.9-intel/egg/setuptools/command/easy_install.py", line 593, in easy_install

      File "build/bdist.macosx-10.9-intel/egg/setuptools/command/easy_install.py", line 623, in install_item

      File "build/bdist.macosx-10.9-intel/egg/setuptools/command/easy_install.py", line 811, in install_eggs

      File "build/bdist.macosx-10.9-intel/egg/setuptools/command/easy_install.py", line 1017, in build_and_install

      File "build/bdist.macosx-10.9-intel/egg/setuptools/command/easy_install.py", line 1005, in run_setup

    distutils.errors.DistutilsError: Setup script exited with error: command 'cc' failed with exit status 1
    Complete output from command python setup.py egg_info:
    OS/X: confusion between 'cc' versus 'gcc' (see issue 123)

will not use '__thread' in the C code

c/_cffi_backend.c:14:10: fatal error: 'ffi.h' file not found

#include <ffi.h>

         ^

1 error generated.

Traceback (most recent call last):

  File "<string>", line 16, in <module>

  File "/Users/cody/virtualenvs/analytics/build/bcrypt/setup.py", line 104, in <module>

    "Programming Language :: Python :: 3.3",

  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/core.py", line 112, in setup

    _setup_distribution = dist = klass(attrs)

  File "build/bdist.macosx-10.9-intel/egg/setuptools/dist.py", line 239, in __init__

  File "build/bdist.macosx-10.9-intel/egg/setuptools/dist.py", line 264, in fetch_build_eggs

  File "build/bdist.macosx-10.9-intel/egg/pkg_resources.py", line 620, in resolve

    dist = best[req.key] = env.best_match(req, ws, installer)

  File "build/bdist.macosx-10.9-intel/egg/pkg_resources.py", line 858, in best_match

    return self.obtain(req, installer) # try and download/install

  File "build/bdist.macosx-10.9-intel/egg/pkg_resources.py", line 870, in obtain

    return installer(requirement)

  File "build/bdist.macosx-10.9-intel/egg/setuptools/dist.py", line 314, in fetch_build_egg

  File "build/bdist.macosx-10.9-intel/egg/setuptools/command/easy_install.py", line 593, in easy_install



  File "build/bdist.macosx-10.9-intel/egg/setuptools/command/easy_install.py", line 623, in install_item



  File "build/bdist.macosx-10.9-intel/egg/setuptools/command/easy_install.py", line 811, in install_eggs



  File "build/bdist.macosx-10.9-intel/egg/setuptools/command/easy_install.py", line 1017, in build_and_install



  File "build/bdist.macosx-10.9-intel/egg/setuptools/command/easy_install.py", line 1005, in run_setup



distutils.errors.DistutilsError: Setup script exited with error: command 'cc' failed with exit status 1

----------------------------------------
Command python setup.py egg_info failed with error code 1 in /Users/cody/virtualenvs/analytics/build/bcrypt

Answer 1

在theseposts 的帮助下，我终于可以使用以下功能了：

brew install pkg-config libffi
sudo bash
export CFLAGS=-Qunused-arguments
export CPPFLAGS=-Qunused-arguments
export PKG_CONFIG_PATH=/usr/local/Cellar/libffi/3.0.13/lib/pkgconfig/
pip install bcrypt

Answer 2

不使用 sudo 和 CFLAGS 和 CPPFLAGS（pip 不需要）：

$ brew install pkg-config libffi
$ export PKG_CONFIG_PATH=/usr/local/Cellar/libffi/3.0.13/lib/pkgconfig/
$ pip install bcrypt

Answer 3

15 年 8 月 26 日更新

我认为TA的回答更好，因为它是由系统处理的。

---

首先，我讨厌安装 Brew 或 Ports，但这是另一个问题。

我一直在尝试pip install cryptography，这取决于cffi，它导入ffi.h。

我很好奇为什么没有人提到他（和我，以及我相信其他人）安装了 Xcode 的 ffi：

locate ffi.h
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/include/ffi/ffi.h

因为错误是专门关于“找不到”ffi.h 使用以下构建命令：

c/_cffi_backend.c:14:10: fatal error: 'ffi.h' file not found
#include <ffi.h>
...
...
/usr/bin/clang ...{omitted}... I/usr/include/ffi -I/usr/include/libffi

我有ffi.h，只是系统认为应该在/usr/include/...。

我的/usr/include 目录恰好是空的，并且没有链接到任何东西，所以我只是将有问题的目录/文件链接到了找不到它的地方：

ln -fs {THAT_XCODE_SDK_FFI_PATH_FROM_ABOVE} /usr/include/ffi

我现在可以安装和构建 cffi 和密码学了。

在理解构建链/链接动态方面我非常新手，如果这不好，我不明白......所以，请告诉我。

Answer 4

已经为我安装了 Xcode（正如问题本身所提到的，它确实提供了 ffi.h 标头），但由于某种原因，它没有填充 /usr/include（正如 Zachary Young 所提到的）。我四处寻找为什么没有填充 /usr/include 并发现以下命令修复了它：

$ xcode-select --install

Missing /usr/include after Yosemite and Xcode install?