我尝试在我的Windows7 64位计算机上安装Fabric，得到的只是一条糟糕的错误消息：

building 'Crypto.Random.OSRNG.winrandom' extension

warning: GMP or MPIR library not found; Not building
Crypto.PublicKey._fastmath.

error: Unable to find vcvarsall.bat

在这个类似的问题错误中没有一个答案：找不到vcvarsall.bat对我有用。怎么办？

我认为根本原因如下：

Some Windows users whose Python is 64-bit have found that the PyCrypto
dependency winrandom may not install properly, leading to
ImportErrors. In this scenario, you’ll probably need to compile
winrandom yourself via e.g. MS Visual Studio. See #194 for info.

我已经能够通过从Michael Foord的网站下载和安装一个加密二进制文件，然后重新安装Fabric来解决这个问题。非常感谢迈克尔！