Collect performance-report hardware after the first frame and preserve logs, input and CLI pipes while suppressing background terminal windows.
Co-Authored-By: OpenAI Codex (GPT-6.1 Sol) <noreply@openai.com>
The game writes logs/latest.log in its home like vanilla's log4j config
(client-1.21.2.xml): [HH:mm:ss] [thread/LEVEL]: message, rolled at start and
at midnight to logs/<date>-<n>.log.gz, seven a day. Messages go through the
log facade and still print their old text on stderr.
A main-thread panic or a fatal error writes
crash-reports/crash-<date>_<time>-client.txt (error, stack, Horizon and
Minecraft versions, OS, CPU, memory, GPU adapter, render settings, resource
packs, world, last 50 log lines). Development builds crash on purpose with
HORIZON_DEBUG_CRASH.
The launcher shows "Horizon crashed" when the game it started ends badly,
with Open report, Copy report, Open logs folder and Report on Discord;
Settings gets a Logs row. horizon-launcher logs and horizon-ctl logs
(--lines N, --crash) print the log's end or the newest report, and both MCP
servers have a logs tool.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>