For the chipotle chile-sugar rim: Combine the sugar and chipotle powder; mix well and spread on a small plate. Moisten half the rim of a 10-ounce rocks glass with the lime wedge and press into the chipotle sugar to rim half of the edge. Fill the glass with ice and set aside.
For the drink: Fill a mixing glass 2/3 of the way with ice then add the mezquila, agave nectar, lime juice, BBQ sauce and bitters. Cap the mixing glass with the shaker tin and shake vigorously for 10 to 15 seconds.