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

[Hanna Reitz <hreitz@redhat.com>]

On 22.09.21 22:38, John Snow wrote:
>
>
> On Wed, Sep 22, 2021 at 4:37 PM John Snow <jsnow@redhat.com 
> <mailto:jsnow@redhat.com>> wrote:
>
>
>     On Fri, Sep 17, 2021 at 7:16 AM Hanna Reitz <hreitz@redhat.com
>     <mailto:hreitz@redhat.com>> wrote:
>
>
>         Question is, when “can we use” mypy >= 0.920? Should we check the
>         version string and append this switch as required?
>
>
>     The answer to that question depends on how the block maintainers
>     feel about what environments they expect this test to be runnable
>     under. I lightly teased kwolf once about an "ancient" version of
>     pylint they were running, but felt kind of bad about it in
>     retrospect: the tests I write should "just work" for everyone
>     without them needing to really know anything about python or
>     setting up or managing their dependencies, environments, etc.
>
>     (1) We can use it the very moment it is released if you're OK with
>     running 'make check-dev' from the python/ directory. That script
>     sets up its own virtual environment and manages its own
>     dependencies. If I set a new minimum version, it will always use
>     it. (Same story for 'make check-tox', or 'make check-pipenv'. The
>     differences between the tests are primarily on what other
>     dependencies they have on your environment -- the details are
>     boring, see python/Makefile for further reading if desired.)
>
>     (2) Otherwise, it depends on how people feel about being able to
>     run this test directly from iotests and what versions of
>     mypy/pylint they are using. Fedora 33 for instance has
>     0.782-2.fc33 still, so I can't really "expect" people to have a
>     bleeding-edge version of mypy unless they went out of their way to
>     install one themselves. (pip3 install --user --upgrade mypy, by
>     the way.) Since people are used to running these python scripts
>     *outside* of a managed environment (using their OS packages
>     directly), I have largely made every effort to support versions as
>     old as I reasonably can -- to avoid disruption whenever I possibly
>     can.
>
>     So, basically, it kind of depends on if you want to keep 297 or
>     not. Keeping it implies some additional cost for the sake of
>     maximizing compatibility. If we ditch it, you can let the scripts
>     in ./python do their thing and set up their own environments to
>     run tests that should probably "just work" for everyone.297 could
>     even just be updated to a bash script that just hopped over to
>     ./python and ran a special avocado command that ran /only/ the
>     iotest linters, if you wanted. I just felt that step #1 was to
>     change as little as possible, prove the new approach worked, and
>     then when folks were comfortable with it drop the old approach.
>
>
> Oh, uh, and to answer your more concrete question: Nah, we don't need 
> to conditionally append this workaround. The speed lost from making 
> the check incremental is made up for by not invoking the tool 20 
> times, so it's OK to just unconditionally add it for now.

Well, yes, but it could be even faster!

And also it would save us from the pain of waiting and judging when it’s 
reasonable to drop `--no-incremental`, and/or just forgetting that this 
workaround even exists.  If we checked the version string, it would be 
OK to just forget about it, I think.

Hanna