PSA: remove pybind11 support

MLIR
1

I would like to remove support for pybind11 from the MLIR Python bindings:

Support for pybind11 is now deprecated for a year and it’s blocking some other improvements I’m planning for the bindings. But if you’re still not ready, I’m fine waiting until say Jan 31 '26? So “speak now or forever hold your peace” :smiley:.

Note, I tried to do this a couple of months ago and it didn’t stick, both because I replaced pip install nanobind with FetchContent_Declare and because it caught some people by surprise. Hence, this PSA (and no use of FetchContent_Declare this time).

2

I’m not MLIR contributor, but I’d be looking at Jan 13 and thinking whether this change should get into 22 release. In Clang we’d almost certainly hold off until after the release branch is created in those circumstances.

3

Thanks for the tip - I think if no one opposes then we can make that date (the PR itself is “finished”) but if not I’m not too worried (my intuition is most MLIR projects are living close to ToT anyway).

4

Merged!