--disallow-incomplete-defs does not print errors when run without this argument previously

[srittau]

I have a fairly large project that is partly type-checked. Using the following mypy.ini file it typechecks without errors:

[mypy]
ignore_missing_imports = True
; disallow_subclassing_any = True
check_untyped_defs = True
; disallow_untyped_defs = True
; disallow_incomplete_defs = True
warn_redundant_casts = True
; warn_return_any = True
warn_unused_ignores = True
warn_unused_configs = True
strict_optional = True

Running it with --disallow-incomplete-defs or --disallow-untyped-defs still produces lots of warnings.

Since upgrading to mypy 0.590, running mypy, followed by mypy --disallow-incomplete-defs will not output any warnings, although the latter command should produce loads. mypy --disallow-untyped-defs on the other hand still works. When running mypy --disallow-incomplete-defs after removing .mypy_cache or after mypy --disallow-untyped-defs, it will again print the warnings, until the next time mypy is run without arguments. --no-incremental also works around this problem.

I tried to create a minimal test case with just one file exhibiting that problem, but unfortunately that worked correctly.

I tested it with Python 3.5.5.

[ilevkivskyi]

This is likely caused by the switch to incremental mode by default (may be a problem with import cycles). As a temporary workaround you can use --no-incremental on 0.590, but since this is a regression, I think this is high priority to fix.

[srittau]

I managed to produce a minimal test case:

srittau@moby:~$ mkdir mypy-bug && cd mypy-bug
srittau@moby:~/mypy-bug$ mkdir -p pylibs/mypkg
srittau@moby:~/mypy-bug$ cat > pylibs/mypkg/__init__.py
def func(foo) -> bool:
    return False
srittau@moby:~/mypy-bug$ mypy --disallow-incomplete-defs pylibs
pylibs/mypkg/__init__.py:1: error: Function is missing a type annotation for one or more arguments
srittau@moby:~/mypy-bug$ mypy pylibs
srittau@moby:~/mypy-bug$ mypy --disallow-incomplete-defs pylibs
srittau@moby:~/mypy-bug$ 

[gvanrossum]

I'm guessing that disallow_incomplete_defs should be included in the set PER_MODULE_OPTIONS in mypy/options.py.

[gvanrossum]

Maybe this was fixed by #5414? My suggestion was implemented there.

[srittau]

I'll check when I get home.

[srittau]

This bug is reproducible with mypy 0.620, but not with mypy HEAD. Closing.