谬误形容

pip install requirements.txt 
Defaulting to user installation because normal site-packages is not writeable
ERROR: Could not find a version that satisfies the requirement requirements.txt (from versions: none)
ERROR: No matching distribution found for requirements.txt
vagrant@vagrant:/vagrant$ sudo pip install requirements.txt 

解决办法

少了 -r 参数，换成如下命令

pip install -r requirements.txt