add nanobind include path to CMakeLists

[andrej]

For some reason, this now seems to be required for me to be able to build? Otherwise, I get include errors. Solution found by Claude, please scrutinize because I don't 100% understand why this is now suddenly required.

[jgmelber]

@erwei-xilinx did you come across this in the EUDSL bump?

[Copilot]

Pull request overview

Updates the Python bindings CMake configuration to explicitly use nanobind and to add nanobind’s include directory to the build interface, addressing build-time include resolution issues for the Python extension modules.

Changes:

• Set PYTHON_BINDINGS_LIBRARY nanobind on the MLIR and XRT Python extension declarations.
• Add ${NB_DIR}/include to the build include paths for AIEPythonExtensions.MLIR (python-passes/omnibus branch).

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[Copilot]

${NB_DIR} is not defined anywhere in this repository, so if it isn't set by the included AddMLIRPython module/configure step it will expand to an empty string here and effectively add /include to the include path. Consider guarding this with an explicit if (NOT DEFINED NB_DIR) error (or deriving the include directory from the nanobind CMake package/target) so misconfiguration fails fast with a clear message instead of producing a confusing include path.

[fifield]

@erwei-xilinx did you come across this in the EUDSL bump?

I ran into similar issue and it went away by updating llvm + eudsl.

[erwei-xilinx]

Let me investigate

[hunhoffe]

I also ran into this issue, but it disappeared when I got fresh eudsl + llvm

[erwei-xilinx]

CC investigated this. The PYTHON_BINDINGS_LIBRARY parameter was removed from upstream LLVM's declare_mlir_python_extension CMake function in commit 3d7018c70b97 ("[MLIR][Python] remove pybind11 support (#172581)", Dec 19 2025) by @makslevental. Since pybind11 had been deprecated for over a year, that commit made nanobind the only (and default) binding library, so the parameter is no longer accepted.

mlir-aie's current main branch pins LLVM at 979132a02d14 (Feb 2026), which already includes that removal. PR #2918 specifically removed PYTHON_BINDINGS_LIBRARY nanobind from these exact call sites for this reason — passing the now-unrecognized parameter causes CMake to treat it as unparsed arguments and forward them as literal linker flags (-lPYTHON_BINDINGS_LIBRARY -lnanobind), leading to linker failures.

Re-adding PYTHON_BINDINGS_LIBRARY nanobind here would reintroduce that breakage on the current LLVM version. The include path issue (${NB_DIR}/include) is likely a separate problem — as @fifield and @hunhoffe noted, it goes away with a fresh LLVM + eudsl build, which suggests it's a stale build artifact rather than a missing CMake configuration.

[andrej]

Excellent, thanks for the quick helpful replies. I'm using build-mlir-aie-from-wheels.sh and it probably just picked up an old cached version of the LLVM wheel. Let me retry after deleting it.