Seeing a device is not computing on it. For llama.cpp on a machine with
NVIDIA GPUs, engine-check now loads a small GGUF (--model, or the smallest in
the weights cache) with every layer on the GPU, asks for one token, and
reads from llama.cpp's own output where the layers went: a build that
computes on the CPU fails, naming the fix. With no --bin it checks the build
the agent installed under /opt/llmgw/engines.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
