OK, someone needs to re-explain the advantage of stowfs then. If
we have some front-end to download the package, pkgadd, pkgrm, etc.
What's the advantage of another layer??
It automates the "symlink-farm" creation. You also can implement
things like special nodes that can be modifed by users/programs, or
read to get information about the package. So I can access
/stow/PKG-VER/,dependencies and get a list of unfullfilled
dependencies. Maybe people have more ideas for interesting nodes that
could be made avaiable by stowfs that might be useful.
pkgadd/pkgrm run post/pre scripts, since they are interactive tasks.
Having cp do this, would be quite counter intuitive; and quite hard to
implement safetly. You would for example have to modify almost all
syscalls that handle file operations to handle this.
Also, it doesn't follow the KISS principle.
Not to mention: What happens if the stowfs translator dies? Do I
lose access to all my apps??
Same thing that will happen when your root file-system dies; total
system havoc. This shouldn't happen to begin with.
To counter your worries about stowfs, think about what would happen if
the symlink translator points to /lib/ld.so (or any other important
file) would crash. If you feel adventurous, you could even try it on a
live system.