The movie was some kind of anthology of comedy (cf Amazon Women on the Moon). It may or may not have had a horror-movie angle for some or all of the comedy bits. I believe it was released in the early-1980s, and it was an HBO staple by the mid-80s.
Between the comedy bits, there were scenes of the audience “watching the movie”. In one scene, a gentleman with a large Afro hairstyle sits in front of a Cheech-Marin soundalike (I thought for years that it WAS Cheech, but an IMDB search came up empty). Anyway, after the Afro guy sits down, the Cheech-like guy proclaims “Yo man, it’s an eclipse!”.
What the heck movie is that? Can’t believe I can’t come up with the title.
The movie you’re looking for is It Came from Hollywood, a compilation of wonderfully bad films, and the segment you’re talking about does feature Cheech and Chong.
EDIT: … and I see why I missed the movie title under Marin’s IMDB bio. He was billed as playing himself, which placed the entry into the “Self” section of his IMDB page instead of the main acting-credits section.