I've been exploring the Fuchsia operating system, and while they have per-process namespaces, they don't have a utility like plan 9's bind, nor a method of supporting it by default in their system libraries. I've made some progress on adding it (https://imgur.com/HELWbrQ), but enthusiasm for the concept seems lukewarm, and I'm coming to the point where I feel I'm going to need to make a strong argument for why it should be a feature of their per-process namespace filesystem. As someone who's neither on their team nor an employee of google, I feel that I'm going to need to make a damn good argument - and I'd very much like to, as it really, *really* is something I'd like to have easily within reach in a modern OS, and it seems like such a low-hanging fruit of a feature.

I have two scenarios currently I feel make a strong argument for the inclusion of bind: one is running tests on an install of a product while still being able to do development on it, by using a bind to redirect the development dll to the install's dll in the process I'm developing in; and the other an example of when a bind would just be convenient, such as a certain process needing python2 instead of python3 on a system which defaults to python 3, and have scripts that reference #/bin/python.

So, I'd like to hear the community's thoughts on other uses of bind. I think they'd be useful both for making my case for bind, and in thinking about my continuing implementation of the command. I also want to implement union mounting in the future (which I can get very-close-to-being-free with my changes for umount), but right now bind is my focus.

Thanks for your time.

Marshall