PANTS_DEBUG mode is not fully faithful to the `./pants` implementation.

[jsirois]

The ./pants implementation has a best-effort attempt to catch cases where you attempt to PANTS_DEBUG and do not turn off pantsd:
https://github.com/pantsbuild/setup/blob/15988fe15cc87031235ecd0e94ebc38df692a910/pants#L498-L501

Either the same best-effort could be made (note that PANTS_PANTSD is not checked nor is the --pantsd=False form, etc) or scie-pants could just force --no-pantsd and maybe emit a warning it is doing so.