/display/monitors must never answer empty AND silent — the console reads that as "the host is broken". But gamescope is nested: it owns no physical heads by construction, so empty-and-silent is the correct answer there, not an unexplained one. Any dev box that has ever been in game mode keeps gamescope-0 sockets in its runtime dir, so detect() resolves gamescope and the test failed on the machine rather than on the code (found running the suite on .136). Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>