in dev-tools/mage/gotool/go.go [330:343]
func (a *Args) build() []string {
args := make([]string, 0, 2*len(a.flags)+len(a.pos))
for k, values := range a.flags {
for _, v := range values {
args = append(args, k)
if v != "" {
args = append(args, v)
}
}
}
args = append(args, a.pos...)
return args
}