Dash deliberately ignores HOST whenever it detects that it is running inside a Conda-managed environment (CONDA_PREFIX is in os.environ).
This guard was added while fixing #3069 because some Conda activators export an invalid host name (e.g. x86_64-conda-linux-gnu
), which breaks Flaskās socket binding.
https://github.com/plotly/dash/issues/3069
https://github.com/plotly/dash/pull/3130