Running

func run --verbose --builder=pack --build=1

in python function actually runs with host because container is false by default

Contrary running

func run --verbose --builder=pack --build=1 --container=1

runs as expected

I suspect a simple check /validation somewhere is missing for the combination of builder container etc. Maybe it's build config value is not checked ( result of config, ENVs, flags) etc.

/assign
/bug