--incremental --follow-imports=silent run separately on different files does not produce errors #3639
Description
On mypy version 0.511
# a.py
import b
b.foo(1, 2)
# b.py
def foo(a, b):
# type: (int, int) -> str
return a + b
> mypy --incremental --py2 --follow-imports=silent a.py # No error, as expected.
> mypy --incremental --py2 --follow-imports=silent b.py # No error where it was expected!
> mypy --incremental --py2 --follow-imports=normal b.py # Error