Why I fail so bad to check for memory leak with this code?

[Marco Sulla]

This naif code shows no leak:

import resource
import pickle

c = 0

while True:
    pickle.dumps(iter([]))

    if (c % 10000) == 0:
        max_rss = resource.getrusage(resource.RUSAGE_SELF).ru_maxrss
        print(f"iteration: {c}, max rss: {max_rss} kb")

    c += 1