math/bits dependency not downloaded

[Michionlion]

After running go install github.com/golang/dep/cmd/dep but not setup.sh, the following happens:

$ go build -o bin/neighbor cmd/neighbor/main.go 
vendor/golang.org/x/crypto/ssh/cipher.go:19:2: cannot find package "math/bits" in any of:
	/home/michionlion/go/src/github.com/mccurdyc/neighbor/vendor/math/bits (vendor tree)
	/usr/lib/go-1.8/src/math/bits (from $GOROOT)
	/home/michionlion/go/src/math/bits (from $GOPATH)

My Go installation is as vanilla as it gets but I'll try and see if it's that.

[Michionlion]

Installing from source instead of using the default golang package (with 1.8) on Ubuntu fixed this issue. No idea of the cause -- perhaps some cipher algorithms aren't included since it must be open source?