Issue Description:

As `fork` is not allowed we have to resort to `posix_spawn` which needs a list of environment variables to set for the child. We currently have no method of getting to such a list as the environment is not reachable, neither is there something in `Process` nor can we access the `environ` variable that is exported from the c library.

As I can see `Foundation` does a call to a `CoreFoundation` method to get that. If we do not want to use `Foundation` we're screwed.