:: String -> Int is:exact -package:gpolyline -package:numeric-prelude -package:ghc-lib-parser -package:vty -package:speculate -package:hledger-lib -package:dbus -package:hxt -package:base package:ChasingBottoms

nonBottomError s raises an exception (AssertionFailed) that is not caught by isBottom. Use s to describe the exception.