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

stable-retro-turbo
1.0.0.post21

This version was deleted from PyPI around 2026-07-11. Installing fails with:
$ pip3 install stable-retro-turbo==1.0.0.post21 ERROR: Could not find a version that satisfies the requirement stable-retro-turbo==1.0.0.post21
View other deleted versions of stable-retro-turbo

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/2026-07-10/ \ stable-retro-turbo==1.0.0.post21
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Or, download files manually

And install manually via pip:
stable_retro_turbo-1.0.0.post21-cp314-cp314-macosx_14_0_arm64.whl (77.7MB)
stable_retro_turbo-1.0.0.post21-cp314-cp314-manylinux_2_26_x86_64.manylinux_2_28_x86_64.whl (80.5MB)