No-config debug uses default system Python on MacOS, not the active Python in terminal

Running VS code on MacOS, for a script go.py:

import sys
print(sys.prefix)

I get the following in a VS code integrated terminal where I have activated a Python 3.12 conda environment:

$ python -V
Python 3.12.8
$ python go.py
/Users/aldcroft/miniconda3-arm/envs/ska3-flight-2025.0rc2
$ debugpy go.py
/Applications/Xcode.app/Contents/Developer/Library/Frameworks/Python3.framework/Versions/3.9

If I use the traditional configured debug in VS code, then I get the expected results (Python 3.12.8 from my conda env). I had thought that no-config debug should just work and pick up the current environment in the terminal window.