"invalid argument" error on mips/openwrt

I try to run a go app on openwrt on a router using mips, when trying to create a new datastore I get "invalid argument" error.

```
db, err = bolt.Open("mydb", 0600, &bolt.Options{})

// err.Error() = invalid argument 
```

I use bbolt v1.4.0
mips gnu/linux

