The Yakima Sling, A Beer Cocktail? (Common Man Cocktails)

Now this is very interesting. Tequila, beer, and grapefruit all in one go? Hmmmmm. Seems pretty well rounded, btw.

Recipe
1 1/2 oz. Reposado Tequila
3/4 oz. Grapefruit Juice
1/4 oz. Cinnamon Simple Syrup
1/2 oz. Lime Juice
3 oz. IPA Beer