View source for Pip install problem

<pre>
pip install cffi
</pre>

But vcvarsall.bat exists on the system. This is because python 2.7 does not support MS Visual Studio ver > 8.0.
To fix it:
modifing the Lib\distutils\msvc9compiler.py can make it support vs 10.0
change 304 line 
<pre>
VERSION = get_build_version()
</pre> 
to 
<pre>
VERSION = 10.0
</pre>
and add, 
<pre>
ld_args.append('/MANIFESTFILE:' + temp_manifest) #line 684
ld_args.append('/manifest')
</pre>