RE: https://fosstodon.org/@adamchainz/117017044548701755
"Wheels are also now built with frame pointers enabled, per the PEP 831 change in Python 3.15. Frame pointers are a debugging feature for low-level languages like C, which allow debuggers to reconstruct the call stack of a program. Python has decided to enable frame pointers by default and encourage the ecosystem to do so as well, to make debugging easier for us all, so time-machine is joining the party."
Enabled by default for 3.15, do this for older versions:
Adam Johnson 
@adamchainz@fosstodon.org✍️ time-machine 3.3.0 is out, with Python 3.15 support, performance improvements, subinterpreter support, and various bug fixes.
Check it out, and if you’re using freezegun, try the updated Migration CLI to convert and speed up your tests.