It was a lovely weekend, but shadows were lurking at the Brattle Theatre in Harvard Square, which hosted the first “Noir City: Boston” film festival with 10 well-known or obscure movies of the genre. Eddie Muller, the popular host of “Noir Alley” on Turner Classic Movies and the founder of the Film Noir Foundation, was on hand to introduce each screening and chat with fans. Ned Hinkle, the Brattle’s creative director, said the weekend’s sold-out screenings attracted Brattle regulars and devoted TCM viewers from far and wide. When he introduced Muller before Sunday’s screening of “Force of Evil” starring John Garfield, Hinkle gave a shout-out to Harvard’s Irving House, which provided accommodations for Muller. “They don’t have TCM!” Muller shouted from the wings. Other than that, the longtime San Francisco resident said he enjoyed his stay in Boston which proved a worthy host for a future edition of Noir City.