Fix various build (indexation) errors

When attempting to index `antirez/redis` repository on the `es` branch, I stumbled upon a few build issues, after a few changes I managed to fix them and index redis !

> **Note:** I did not attempt to execute the tests yet.

> **Note:** This PR does not reference a bugzilla issue, just tell me if you'd like to have one.
Another good catch (and a hole in our test coverage)!