Why is conda-build falsely reporting that numpy is not a build requirement?

Question

In response to this command:

conda build --python=3.9 --numpy=1.23 -c dbanas -c defaults -c conda-forge conda.recipe/pyibis-ami/

I'm getting the following error:

ValueError: numpy x.x specified, but numpy not in build requirements.

Here's my meta.yaml file:

{% set name = "pyibis-ami" %}
{% set version = "4.0.6" %}

package:
  version: '{{ version }}'
  name: '{{ name|lower }}'

source:
  path: ../../PyAMI/
  # git_url: https://github.com/capn-freako/PyAMI.git
  # git_rev: {{ version }}
  # git_depth: 1 # (Defaults to -1/not shallow)

build:
  # string: 4961a3_2
  number: 1
  # noarch: python
  script: "{{ PYTHON }} -m pip install . --no-deps --ignore-installed -vv "

requirements:
  run:
    - chaco  >=5.1.0
    - click
    - empy
    - matplotlib
    - numpy x.x
    - parsec >=3.13
    - python
    - scipy

  build:
  # host:
    - chaco  >=5.1.0
    - click
    - empy
    - matplotlib
    - numpy x.x
    - parsec >=3.13
    - python
    - scipy
    - setuptools
    # - vs2019_win-64        # Uncomment for Windows build only.
    # - {{ compiler('c') }}    # Would like to get one of these working, instead of above hack.
    - {{ compiler('cxx') }}

test:
  imports:
    - pyibisami
{snip}

As you can see, I've got: - numpy x.x, in both build: and run: subsections of requirements:.

Why am I getting this error?