I have a conda environment set up to use the development branch of yt. When I just now went to update it I got:
Fetching package metadata .............
CondaHTTPError: HTTP None None
for url <None>
An HTTP error occurred when trying to retrieve this URL.
SSLError(SSLError(SSLError(1, u'[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:590)'),),)