typing error on master in _core/_multierror since exceptiongroup==1.1.3

[jakkdl]

https://github.com/python-trio/trio/actions/runs/6043678194/job/16401102375#step:5:840

 ++ mypy trio --platform linux
trio/_core/_multierror.py:264: error: Signature of "derive" incompatible with supertype "BaseExceptionGroup"  [override]
trio/_core/_multierror.py:264: note:      Superclass:
trio/_core/_multierror.py:264: note:          @overload
trio/_core/_multierror.py:264: note:          def [_ExceptionT <: Exception] derive(self, Sequence[_ExceptionT], /) -> ExceptionGroup[_ExceptionT]
trio/_core/_multierror.py:264: note:          @overload
trio/_core/_multierror.py:264: note:          def [_BaseExceptionT <: BaseException] derive(self, Sequence[_BaseExceptionT], /) -> BaseExceptionGroup[_BaseExceptionT]
trio/_core/_multierror.py:264: note:      Subclass:
trio/_core/_multierror.py:264: note:          @overload
trio/_core/_multierror.py:264: note:          def derive(self, Sequence[Exception], /) -> NonBaseMultiError
trio/_core/_multierror.py:264: note:          @overload
trio/_core/_multierror.py:264: note:          def derive(self, Sequence[BaseException], /) -> MultiError
trio/_core/_run.py:204: error: Unused "type: ignore" comment  [unused-ignore]
Found 2 errors in 2 files (checked 129 source files)
++ EXIT_STATUS=1

bumped in #2782

[A5rocks]

Actually it's cause of a exceptiongroups bump -- I'm just not sure exactly why we use the whole assignment thing instead of just subclassing so I left that for a bit.

[jakkdl]

@CoolCat467 wrote the type stubs in #2742, so they might have an idea?

[CoolCat467]

Basically there was a bit of a mess with overloads and the different overloads accepting things that were too broad and caught other branches of it.

[jakkdl]

Basically there was a bit of a mess with overloads and the different overloads accepting things that were too broad and caught other branches of it.

you up for writing a PR to fix it?

[CoolCat467]

Basically there was a bit of a mess with overloads and the different overloads accepting things that were too broad and caught other branches of it.

you up for writing a PR to fix it?

Sure, I'll take a crack at it.

[CoolCat467]

#2787