I feel strongly from my experience w/ Py3 migrations that it’s imperative you are able to set your ICs only based on the code itself’s compatibility, rather than needing to consider all transitive deps—and then Pants will ensure the result is valid by merging the ICs

i disagree. if you set a constraint based only on the code, then it’s a lie. the code cannot be used without its dependencies. it’s not useful to anyone to know what the constraints of the code would be if it didn’t have any deps.