Python Anaconda错误:无包错误:当前win-64通道中缺少包:

我正试图在我的系统上基于这些 instructions here . 在Windows 10上运行。

git clone https://github.com/fastai/fastai.git
cd fastai
conda create -n fastai python=3.6
activate fastai
conda env update

错误:

Using Anaconda API: https://api.anaconda.org
Fetching package metadata ...............
Solving package specifications: .
NoPackagesFoundError: Packages missing in current win-64 channels:
  - spacy
  - expat
  - libxml2
  - pexpect
  - xz

python--版本

Python 3.6.2 :: Continuum Analytics, Inc.

康达信息

            platform : win-64
        conda version : 4.2.9
     conda is private : False
    conda-env version : 4.2.9
  conda-build version : 2.0.2
       python version : 2.7.12.final.0
     requests version : 2.18.4
     root environment : C:\Users\y\Anaconda2  (writable)
  default environment : C:\Users\y\Anaconda2\envs\fastai
     envs directories : C:\Users\y\Anaconda2\envs
        package cache : C:\Users\y\Anaconda2\pkgs
         channel URLs : https://repo.continuum.io/pkgs/free/win-64/
                        https://repo.continuum.io/pkgs/free/noarch/
                        https://repo.continuum.io/pkgs/pro/win-64/
                        https://repo.continuum.io/pkgs/pro/noarch/
                        https://repo.continuum.io/pkgs/msys2/win-64/
                        https://repo.continuum.io/pkgs/msys2/noarch/
          config file : None
         offline mode : False

我做错了什么?