It does not work for Python 3.9

[GoingMyWay]

I followed this post by using line_profier without magic. However, when I tried to get the stats via python -m line_profiler main.py.lprof, it shows nothing but the following content

Timer unit: 1e-06 s

My current python3.9 and the system is Ubuntu 20.

Besides that, with magic, it shows profile not found!.

[Erotemic]

Can you provide a mwe that demonstrates the failure?