Lil Xan's been getting flak from the hip-hop community all week for calling Tupac's music "boring" ... and it seems the criticism's escalated to real-life harassment.
According to a police report -- obtained by TMZ -- the rapper was at a Del Taco in his hometown of Redlands, CA Thursday afternoon when he was surrounded by a group of high school-aged kids who were upset over his comments about Tupac.
There wasn't a physical fight, but the hostile environment was apparently enough to make Lil Xan run to a nearby YMCA ... where an officer picked him up and escorted him to his car safely.
The report says the large crowd was gathered at the Del Taco for a possible girl fight after school ... so the rapper possibly got caught in the middle of the frenzy. We're told no crime was committed against him, though.
Lil Xan was in town for a meet-and-greet Thursday night, but the way he was greeted is in stark contrast to the last time we saw the "Betrayed" rapper ... when he was flanked by adoring fans in NYC.