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Announcement issue for plugin API changes
#6617 · msullivan opened on Apr 3, 2019
23

Labels Milestones New issue

[1.19 regression] Can no longer use <code>types.NoneType()</code> as a condition in match/case

#20367

· chadhpaine opened

on Dec 5, 2025

An empty generic class is covariant even though the doc says "all user-defined generic classes invariant by default"

#20366

· hyperkai opened

on Dec 5, 2025

type narrowing with <code>isinstance</code> does not work in combination with <code>and</code> and <code>or</code>

#20363

· jgogstad opened

on Dec 4, 2025

<code>TypeIs</code> narrowing of union type in a generic is not working

topic-typeguard-typeis

#20359

· mbikovitsky opened

on Dec 3, 2025

numpy dtype Statement is unreachable with mypy 1.19.0

topic-match-statement

#20358

· acabal33uab opened

on Dec 3, 2025

Incorrect resolution of <code>type[TypeVar]</code> returning <code>TypeVar</code> with <code>numpy</code>

topic-type-variables

#20354

· Dr-Irv opened

on Dec 2, 2025

[1.19 regression] output format overruled by .mypy_cache

topic-error-reporting

#20353

· sjoerdjob-legalsense opened

on Dec 2, 2025

<code>--disable-error-code=unused-ignore</code> should override <code>enable_error_code = ["unused-ignore"]</code>

topic-configuration

topic-error-reporting

#20348

· bersbersbers opened

on Dec 2, 2025

Nondeterministic output when using tuple type vars

#20344

· Apakottur opened

on Dec 1, 2025

[1.19 regression] [mypyc] generator → AssertionError

#20341

· mr-c opened

on Dec 1, 2025

Assertion failure crash with shadowed functools module: assert isinstance(singledispatch_obj, Instance)

#20339

· correctmost opened

on Dec 1, 2025

Swapping some type variables gives incorrect results

priority-1-normal

topic-type-variables

#20336

· randolf-scholz opened

on Nov 30, 2025