package io/fs: unrecognized import path "io/fs" (import path does not begin with hostname)

[danielw1990]

I was trying to install murmur-cli on a NanoPi Neo:

so according to the readme I run: go get -u layeh.com/murmur-cli

and after waiting a few minutes I get:
package io/fs: unrecognized import path "io/fs" (import path does not begin with hostname)