Just curious -- are you using linux emulation? Asked, coz of all the
references to '/usr/pkg/emul/linux/proc/". If I were you, I'd try
unmounting that directory and then trying. (This is just a guesswork
suggestion ... more like thinking aloud on what I'd do if I were in a
similar situation).

"/usr/pkg/emul/linux/proc/" refers to the procfs emulation for linux.
Maybe the presence of that is in someway affecting pkg_install.

Thanks,
Rakhesh