You're looking at StableBuild's Deleted PyPI mirror - where we index all deleted packages from the Python package registry.
spl-transpiler was reported malicious
OSV:MAL-2025-6593 - Malicious code in spl-transpiler (PyPI)

spl-transpiler
0.2.7

This version was deleted from PyPI around 2025-04-15. Installing fails with:
$ pip3 install spl-transpiler==0.2.7 ERROR: Could not find a version that satisfies the requirement spl-transpiler==0.2.7