This is the issue you may observe, when you work behind an authenticating proxy server and want to install Sen2Cor:
Could not fetch URL https://pypi.python.org/simple/glymur/: There was a problem confirming the ssl certificate: EOF occurred in violation of protocol (_ssl.c:590) - skipping
Could not find a version that satisfies the requirement glymur==0.8.6 (from versions: )
No matching distribution found for glymur==0.8.6
It is possible to configure the proxy for pip by creating an ini file, to overcome this issue:
[UserFolder]/pip/pip.ini with the content:
[global]
trusted-host = pypi.python.org
proxy = http://user:password@proxy:port
more details on:
please nothe that this is not an issue of Sen2Cor, but on Network restictions.
However, the installation of Glymur is a key feature, otherwise Sen2Cor will not work properly.