❯ docker run --rm python:3.13-rc bash -c "python -m pip install -qqq 'packaging @ git+https://github.com/pypa/packaging@main' && python -c 'from packaging.requirements import Requirement' && sleep 2 && for i in {1..10}; do python -m timeit -n 1 -r 1 'from packaging.requirements import Requirement'; done"
1 loop, best of 1: 32.3 msec per loop
1 loop, best of 1: 32.1 msec per loop
1 loop, best of 1: 32.2 msec per loop
1 loop, best of 1: 31.5 msec per loop
1 loop, best of 1: 31.3 msec per loop
1 loop, best of 1: 31.5 msec per loop
1 loop, best of 1: 31.5 msec per loop
1 loop, best of 1: 31.4 msec per loop
1 loop, best of 1: 31.3 msec per loop
1 loop, best of 1: 32.1 msec per loop

❯ docker run --rm python:3.13-rc bash -c "python -m pip install -qqq 'packaging @ git+https://github.com/ofek/packaging@import-time-1' && python -c 'from packaging.requirements import Requirement' && sleep 2 && for i in {1..10}; do python -m timeit -n 1 -r 1 'from packaging.requirements import Requirement'; done"
1 loop, best of 1: 16.5 msec per loop
1 loop, best of 1: 16.9 msec per loop
1 loop, best of 1: 17.1 msec per loop
1 loop, best of 1: 16.9 msec per loop
1 loop, best of 1: 17 msec per loop
1 loop, best of 1: 16.8 msec per loop
1 loop, best of 1: 16.9 msec per loop
1 loop, best of 1: 16.9 msec per loop
1 loop, best of 1: 16.9 msec per loop
1 loop, best of 1: 16.9 msec per loop