panic: runtime error: index out of range

[djsuszi]

user@dev:~$ mkdir test
user@dev:~$ export GOPATH=/home/user/test
user@dev:~$ go get -d github.com/tom--bo/sabaviz
user@dev:~$ go build github.com/tom--bo/sabaviz
user@dev:~$ ./sabaviz
panic: runtime error: index out of range

goroutine 1 [running]:
panic(0x5cfe80, 0xc82000a080)
        /usr/lib/go-1.6/src/runtime/panic.go:481 +0x3e6
main.(*CLI).Run(0xc8200b7f18, 0xc82000a240, 0x1, 0x1, 0x0)
        /home/user/test/src/github.com/tom--bo/sabaviz/cli.go:87 +0xa93
main.main()
        /home/user/test/src/github.com/tom--bo/sabaviz/main.go:7 +0xc5
user@dev:~$

what could be wrong ?