synthesized
2.12.post0
This version was deleted from PyPI around 2024-05-11. Installing fails with:
$ pip3 install synthesized==2.12.post0
ERROR: Could not find a version that satisfies the requirement synthesized==2.12.post0

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/2024-05-10/ \
synthesized==2.12.post0
Sign up for StableBuild to get an API key (it's free and takes <60 seconds!)
Or, download files manually
And install manually via pip: