This is a documentary that pretty much does what it says on the can. It takes us within the walls of an out of the way bar where, once the sun goes down, the lights come up and the eponymous Roshell Terranova provides a stage for Mexican men who range from the traditional drag artiste through to those with more existential gender issues. Whilst there isn’t any persecution from the authorities about what they are doing, there isn’t really much trade, as it were, either so most of her custom comes from regulars out to get dolled up to the nines and let their hair down. What doesn’t work so…