TAPACHULA, Mexico — The coolest dive bar in southern Mexico — or, at least the coolest one founded by migrants from Cameroon — was hidden in a mostly residential neighborhood in Tapachula, a city near the border with Guatemala.

It was hard to find, tucked behind an unmarked yellow metal gate and down a grimy passageway. But it offered solace and camaraderie for migrants from sub-Saharan Africa who found themselves stuck in a place far from home, and far from where they wanted to go.

“We are suffering stress,” said Banks, a 25-year-old bar customer who had been a high school physics and chemistry teacher in Uganda but fled because he was persecuted by the government for being gay.

He said government forces had killed his lover and were coming after him. “That’s why I’m drinking,” Banks said, asking to be identified by only by his last name for fear the Ugandan government would find him even here.