After upgrading to Hermes v0.17.0, the Mac's idle power draw jumped from a normal 3-5W to 19W and the fans spun up. Using powermetrics to quantify, ps to localize the process, and sample to grab the call stack, I traced it all the way to Chromium's Rust font engine fontations and the Rust implementation of the Temporal API, temporal_rs, repeatedly formatting time strings and validating glyphs every frame, pinning the GPU at full load. This post records the full investigation.

The Telegram bot kept showing "typing" without ever replying, while the terminal CLI using the exact same model worked perfectly at the same time. It turned out the launchd-started gateway process doesn't inherit the system proxy environment variables, and the proxy lines in .env were commented out — so the gateway connected directly to an overseas API and timed out.

After a Hermes gateway had been online for about 48 hours, the CLI process threw an exception during its shutdown cleanup, which cascaded into the gateway being repeatedly restarted by SIGTERM, forming a vicious "restart interrupts session -> user reconnects -> interrupted again" loop that left the CLI down for about 12 minutes. This post breaks down the full crash chain and root cause.