You're looking at StableBuild's Deleted PyPI mirror - where we index all deleted packages from the Python package registry.

qb-proof-of-concept
0.1.6

This version was deleted from PyPI around 2025-05-22. Installing fails with:
$ pip3 install qb-proof-of-concept==0.1.6 ERROR: Could not find a version that satisfies the requirement qb-proof-of-concept==0.1.6
View other deleted versions of qb-proof-of-concept

Install through StableBuild

You can install this package from StableBuild's PyPI snapshots from before the version was deleted:
pip3 install \ -i https://YOUR_API_KEY.pypimirror.stablebuild.com/2025-05-21/ \ qb-proof-of-concept==0.1.6
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Or, download files manually

And install manually via pip:
qb_proof_of_concept-0.1.6-py2.py3-none-any.whl (2.3KB)
qb_proof_of_concept-0.1.6.tar.gz (1.3KB)