CondaHTTPError: HTTP 520 CONNECTION FAILED for url <https://conda.anaconda.org/numba/linux-64/repodata.json> Elapsed: 00:08.182402 CF-RAY: 86dc1efc5f809664-SJC A remote server error occurred when trying to retrieve this URL. A 500-type error (e.g. 500, 501, 502, 503, etc.) indicates the server failed to fulfill a valid request. The problem may be spurious, and will resolve itself if you try your request again. If the problem persists, consider notifying the maintainer of the remote server.