Cache entry deserialization failed, entry ignored

Question

C:\Users\deypr>pip3 install sklearn  Collecting sklearn    Cache entry deserialization failed, entry ignored    Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: TLSV1_ALERT_ACCESS_DENIED] tlsv1 alert access denied (_ssl.c:777)'),)': /simple/sklearn/    Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: TLSV1_ALERT_ACCESS_DENIED] tlsv1 alert access denied (_ssl.c:777)'),)': /simple/sklearn/    Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: TLSV1_ALERT_ACCESS_DENIED] tlsv1 alert access denied (_ssl.c:777)'),)': /simple/sklearn/    Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: TLSV1_ALERT_ACCESS_DENIED] tlsv1 alert access denied (_ssl.c:777)'),)': /simple/sklearn/    Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: TLSV1_ALERT_ACCESS_DENIED] tlsv1 alert access denied (_ssl.c:777)'),)': /simple/sklearn/    Could not fetch URL https://pypi.python.org/simple/sklearn/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.python.org', port=443): Max retries exceeded with url: /simple/sklearn/ (Caused by SSLError(SSLError(1, '[SSL: TLSV1_ALERT_ACCESS_DENIED] tlsv1 alert access denied (_ssl.c:777)'),)) - skipping   Could not find a version that satisfies the requirement sklearn (from versions: ) No matching distribution found for sklearn 

I am getting this error whenever trying to install any python3 package.

1. What could be the possible reasons?

2. How to fix it ?

Answer 1

Regarding the error/warning message in the question's title:

Cache entry deserialization failed, entry ignored

You can fix it by removing the pip cache, e.g. on Ubuntu:

rm -rf ~/.cache/pip 

Answer 2

It was a network issue. Worked totally fine when I moved to a different network. Thank you everyone :)