Rub roast with salt, and place in a lightly greased 6-qt. slow cooker. Pour beer and 1 can of pineapple tidbits over roast. Process chipotle peppers and remaining can of pineapple in a blender or food processor until smooth. Pour over roast. Cover and cook on LOW 8 to 10 hours or until meat shreds easily with a fork.
Transfer pork to a cutting board; shred with two forks, removing any large pieces of fat. Skim fat from sauce, and stir in shredded pork.
Stir together fresh pineapple and next 5 ingredients. Serve pork in warm tortillas with pineapple mixture and desired toppings.
Read the above negative review but had already started making this. When I tasted the sauce after taking the meat out, it did have a bitter aftertaste, BUT after chilling overnight and skimming the fat off, that bitterness was gone. I did not put the meat in until I knew the sauce was okay. It turned out to be a great meal. I would definitely make it again. My husband was skeptical as the chipotle/adobo sauce is not his favorite flavor, but all the pineapple mellowed out the smokey taste.
Made this with Blue Moon (great beer) and there was an odd aftertaste. Going to freeze what's left over, which is most of it, without the sauce and then repurpose it as pulled pork with tons of BBQ sauce to mask the flavor.