Okay let’s check a few things, which version of go do you have installed?
I’m using 1.10.2 (the most current version)
% go version
go version go1.10.2 darwin/amd64
Assuming your “go workspace” is ~/go then source tree for maiden should be in ~/go/src/github.com/monome/maiden.
You can achieve this by using go get -d github.com/monome/maiden or manually create the directory and clone:
mkdir -pv ~/go/src/github.com/monome && cd ~/go/src/github.com/monome && git clone https://github.com/monome/maiden.git
…then once the source directory is in the right place, cd into that directory and run:
glide install
(aside: I’m using version 0.13.1 of glide)
…from there a build should work. If it doesn’t consider setting the GOPATH environment to point at ~/go and try again.