[WireGuard] RFE: A notion of VERSION (was: Debugging AllowedIps)

[Jason A. Donenfeld]

The best I could come with:

> WIREGUARD_VERSION := $(shell parent_name=$$(readlink -f .. | sed -n 's:.*/[wW]ire[Gg]uard[a-z-]*-\([0-9.]\+\)$$:\1:p');  if [ -d ../.git ]; then echo "git-$$(git rev-parse --shor
t HEAD)"; elif [ -n $parent_name ]; then echo "$$parent_name"; else
echo "unknown"; fi)

Is this reliable, or is this garbage?