I'm thrilled to see this proposal come to review. The journey from the initial discussion in Pitch: System in the toolchain to this really focused and well-written proposal was great to follow! I am very supportive of this proposal and think it fills an important gap in the ecosystem that deserves to be addressed with a standard library type. I have two minor questions:
Extracting documentation content from the proposal
The proposal goes to great length to explain the messy world of path handling across platforms. Can we add this information into an article in our new stdlib documentation catalog?
System.FilePath migration
I think migrating System.FilePath in the package and in any vendor's SDK through ABI redirection is great. I just want to clarify that all the extensions that would be added by SystemPackage and System are only available when developers import either SystemPackage or System, right?