AttributeError during conda build: module 'conda.base.context' has no attribute 'get_prefix'

Question

I'm trying to build a conda package on a Mac M2.

Inside the package folder (containing the __init__.py and meta.yaml) I run:

>> conda build .

I get

Traceback (most recent call last):
  File "/opt/anaconda3/lib/python3.9/site-packages/conda_build/conda_interface.py", line 14, in try_exports
    return getattr(import_module('conda.exports'), attr)
AttributeError: module 'conda.exports' has no attribute 'get_prefix'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/anaconda3/bin/conda-build", line 7, in <module>
    from conda_build.cli.main_build import main
  File "/opt/anaconda3/lib/python3.9/site-packages/conda_build/cli/main_build.py", line 18, in <module>
    import conda_build.api as api
  File "/opt/anaconda3/lib/python3.9/site-packages/conda_build/api.py", line 22, in <module>
    from conda_build.config import (Config, get_or_merge_config, get_channel_urls,
  File "/opt/anaconda3/lib/python3.9/site-packages/conda_build/config.py", line 15, in <module>
    from .conda_interface import root_dir, root_writable
  File "/opt/anaconda3/lib/python3.9/site-packages/conda_build/conda_interface.py", line 119, in <module>
    context_get_prefix = try_exports("conda.base.context", "get_prefix")
  File "/opt/anaconda3/lib/python3.9/site-packages/conda_build/conda_interface.py", line 16, in try_exports
    return getattr(import_module(module), attr)
AttributeError: module 'conda.base.context' has no attribute 'get_prefix'

Both conda and conda-build are updated. Any idea?