Can't build gitlab-workhorse

I was following the gitlab-ce installation from source guide when I got errors building gitlab-workhorse. With Go 1.5.3 I'm getting:

$ sudo -u git -H make
go build -ldflags "-X main.Version=v0.6.5-20160306.105642" -o gitlab-zip-cat ./cmd/gitlab-zip-cat
import cycle not allowed
package ./cmd/gitlab-zip-cat
	imports ../../internal/zipartifacts
	imports archive/zip
	imports bufio
	imports bytes
	imports errors
	imports runtime
	imports runtime/internal/atomic
	imports runtime
Makefile:8: recipe for target 'gitlab-zip-cat' failed
make: *** [gitlab-zip-cat] Error 1

Go 1.6 gives another error:

$ sudo -u git -H make
go build -ldflags "-X main.Version=v0.6.5-20160306.105218" -o gitlab-zip-cat ./cmd/gitlab-zip-cat
# runtime
/usr/local/go/src/runtime/os2_linux_generic.go:12: _SS_DISABLE redeclared in this block
	previous declaration at /usr/local/go/src/runtime/os2_linux.go:8
/usr/local/go/src/runtime/os2_linux_generic.go:13: _NSIG redeclared in this block
	previous declaration at /usr/local/go/src/runtime/os2_linux.go:9
/usr/local/go/src/runtime/os2_linux_generic.go:14: _SI_USER redeclared in this block
	previous declaration at /usr/local/go/src/runtime/os2_linux.go:10
/usr/local/go/src/runtime/os2_linux_generic.go:15: _SIG_BLOCK redeclared in this block
	previous declaration at /usr/local/go/src/runtime/os2_linux.go:11
/usr/local/go/src/runtime/os2_linux_generic.go:16: _SIG_UNBLOCK redeclared in this block
	previous declaration at /usr/local/go/src/runtime/os2_linux.go:12
/usr/local/go/src/runtime/os2_linux_generic.go:17: _SIG_SETMASK redeclared in this block
	previous declaration at /usr/local/go/src/runtime/os2_linux.go:13
/usr/local/go/src/runtime/os2_linux_generic.go:18: _RLIMIT_AS redeclared in this block
	previous declaration at /usr/local/go/src/runtime/os2_linux.go:14
/usr/local/go/src/runtime/os2_linux_generic.go:24: sigset redeclared in this block
	previous declaration at /usr/local/go/src/runtime/os2_linux.go:20
/usr/local/go/src/runtime/os2_linux_generic.go:26: rlimit redeclared in this block
	previous declaration at /usr/local/go/src/runtime/os2_linux.go:22
/usr/local/go/src/runtime/panic1.go:11: paniclk redeclared in this block
	previous declaration at /usr/local/go/src/runtime/panic.go:535
/usr/local/go/src/runtime/panic1.go:11: too many errors
Makefile:8: recipe for target 'gitlab-zip-cat' failed
make: *** [gitlab-zip-cat] Error 2

Does anyone know how to fix it? I'm using the Debian 8.