NIXPACKS_CSHARP_SDK_VERSION, as a shared variable of value 7.0, is not detected by railway

I set this variable in my "live" environment to 7.0, and it works as expected I then shared it with "dev" and "stage", but dev and stage are failing My goal is to have some project-level constants I can reference between all environments instead of copy-pasting them around. I expected that nixpacks parses the shared variable to 7.0 and uses it but it looks like it doesn't. Should I, perhaps, set it inside the project itself somewhere?