无法在ioweb2015克隆上提供服务

Question

I cloned the ioweb2015 git repository and then tried to build it. But I can't get gulp serve to work. It fails with

 Starting 'sass'...
jwt.go:28:2: cannot find package "github.com/dgrijalva/jwt-go" in any of:
    /usr/lib/go/src/github.com/dgrijalva/jwt-go (from $GOROOT)
    /home/ana/woop/ioweb2015/src/github.com/dgrijalva/jwt-go (from $GOPATH)
async.go:23:2: cannot find package "golang.org/x/net/context" in any of:
    /usr/lib/go/src/golang.org/x/net/context (from $GOROOT)
    /home/ana/woop/ioweb2015/src/golang.org/x/net/context (from $GOPATH)
auth.go:30:2: cannot find package "golang.org/x/oauth2" in any of:
    /usr/lib/go/src/golang.org/x/oauth2 (from $GOROOT)
    /home/ana/woop/ioweb2015/src/golang.org/x/oauth2 (from $GOPATH)
auth.go:31:2: cannot find package "golang.org/x/oauth2/jwt" in any of:
    /usr/lib/go/src/golang.org/x/oauth2/jwt (from $GOROOT)
    /home/ana/woop/ioweb2015/src/golang.org/x/oauth2/jwt (from $GOPATH)

I'm on Ubuntu, and I installed go 1.4.2. Go env looks like this:

GOARCH="386"
GOBIN=""
GOCHAR="8"
GOEXE=""
GOHOSTARCH="386"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/ana/woop/ioweb2015"
GORACE=""
GOROOT="/usr/lib/go"
GOTOOLDIR="/usr/lib/go/pkg/tool/linux_386"
CC="gcc"
GOGCCFLAGS="-fPIC -m32 -pthread -fmessage-length=0"
CXX="g++"
CGO_ENABLED="1"

So, any ideas on this?