Cannot get package meta when requirement file uses --follow-links

[pilosus]

To reproduce:

1. Create a requirements.txt

-f https://download.pytorch.org/whl/torch_stable.html
torch==1.7.0+cpu

2. Pass in to the checker and get an error

lein run --requirements requirements.txt
torch:1.7.0+cpu                     Error                                                   Error      

The problem is that we plug in an external link with a package version that is absent from the global PyPI index. That's why we cannot compare versions and get the error