I upgraded 
pkg; pkg-static from 1.3.7 to 1.3.8 without too much trouble only because I had backup pkg-static binaries... still unsure of how to proceed next time. pkg was segfaulting after the initial deinstall-to-reinstall and inability to install (can't forumulate that sentence to be more clear, I am unsure of the precise CLI which occurred...; ) rebooted; still segfaulting; Was able to install the newer version (now that the older version was copied to /usr/local/bin; IOW using the backup binary and its libpkg.