Re: [PATCH v3 14/16] iotests/linters: Add workaround for mypy bug #9852

[Hanna Reitz <hreitz@redhat.com>]

On 16.09.21 06:09, John Snow wrote:
> This one is insidious: if you use the invocation
> "from {namespace} import {subpackage}" as mirror-top-perms does,
> mypy will fail on every-other invocation *if* the package being
> imported is a package.
>
> Now, I could just edit mirror-top-perms to avoid this invocation, but
> since I tripped on a landmine, I might as well head it off at the pass
> and make sure nobody else trips on the same landmine.
>
> It seems to have something to do with the order in which files are
> checked as well, meaning the random order in which set(os.listdir())
> produces the list of files to test will cause problems intermittently.
>
> mypy >= 0.920 isn't released yet, so add this workaround for now.
>
> See also:
>   https://github.com/python/mypy/issues/11010
>   https://github.com/python/mypy/issues/9852
>
> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>   tests/qemu-iotests/linters.py | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/tests/qemu-iotests/linters.py b/tests/qemu-iotests/linters.py
> index 4df062a973..9c97324e87 100755
> --- a/tests/qemu-iotests/linters.py
> +++ b/tests/qemu-iotests/linters.py
> @@ -100,6 +100,9 @@ def run_linters(
>                   '--warn-unused-ignores',
>                   '--no-implicit-reexport',
>                   '--namespace-packages',
> +                # Until we can use mypy >= 0.920, see
> +                # https://github.com/python/mypy/issues/9852
> +                '--no-incremental',
>                   filename,
>               ),

I’m afraid I still don’t really understand this, but I’m happy with this 
given as the reported workaround and you saying it works.

Reviewed-by: Hanna Reitz <hreitz@redhat.com>

Question is, when “can we use” mypy >= 0.920?  Should we check the 
version string and append this switch as required?

Hanna