macos architecture error when building in esp-idf - "frozen runpy"

Question

I am trying to get esp-idf working on a M1 Macbook Air. It installed without errors, but fails when building one of the examples.
I can set the target chip OK in the example, but when I try to build, I get a CMake error:

-- Detecting CXX compile features - done  
-- Building ESP-IDF components for target esp32  
CMake Error at /Users/andrew/esp/esp-idf/tools/cmake/build.cmake:552 (message):  
Traceback (most recent call last):
   File "<frozen runpy>", line 189, in _run_module_as_main  

which points to a Macro, so I have no idea what its input is.

      execute_process(COMMAND ${python}  
        "-m"  
        "idf_component_manager.prepare_components"  
        "--project_dir=${project_dir}"  
        "--lock_path=${dependencies_lock_file}"  
        "--interface_version=${component_manager_interface_version}"  
        "prepare_dependencies"
        "--local_components_list_file=${local_components_list_file}"  
        "--managed_components_list_file=${managed_components_list_file}"  
        RESULT_VARIABLE result  
        ERROR_VARIABLE error)  
    
        if(NOT result EQUAL 0)  
          message(FATAL_ERROR "${error}")  
        endif()  

Within the long error message, there is repeated a few times

   mach-o file, but is an incompatible architecture (have 'arm64', need 'x86_64')

This seems to be after a failed import -

ImportError: dlopen(/Users/andrew/.espressif/python_env/idf5.3_py3.12_env/lib/python3.12/site-packages/pydantic_core/_pydantic_core.cpython-312-darwin.so, 0x0002):

That file exists, but is a 4MB document file containing all sorts of characters with no recognizable beginning to the file.

I have successfully installed esp-idf on a M1 Mac Mini, and followed the same steps for the MBA. This is the final test step.

For reference, CMake is the latest version 3.31.1 and was installed before esp-idf. Python is version 3.12 (the only version on the MBA). CMake, Python, VSCode have all been cleanly re-installed.

Any ideas/pointers?