Problem

nix profile install github:cjpais/Handy fails with hash mismatch:

error: hash mismatch in fixed-output derivation
  specified: sha256-tTswFYLCPGtMbHAb2bQMsklRiRCVXLrtu4pQC8IHdqQ=
  got:       sha256-7IUZZriIVmqf85O49w9tCrTKfQURuAOM+k3sKVyigFk=

Cause

The AppImage at the download URL was updated but the hash in the flake wasn't updated to match.

Fix

Update the hash in flake.nix to: sha256-7IUZZriIVmqf85O49w9tCrTKfQURuAOM+k3sKVyigFk=