a = []
for i in range(10):
    for j in range(100):
        a.append(j)

ruff version 0.1.0

This rule outputs
test-perf.py:4:9: PERF402 Use `list` or `list.copy` to create a copy of a list
Which while correct in that something should be done here, it really should be calling .extend() not the list or list.copy() constructor. Doing

a = []
for i in range(10):
    a = list(range(100))

would yield an invalid result.