Pantheon runs targeted stress and diagnostic workloads against NVIDIA and AMD GPUs: power viruses, memory diagnostics (march tests, disturb and retention patterns), interconnect and AI-shaped workloads, with RAS/ECC snapshots collected on every run. The package carries the kernel sources rather than prebuilt binaries; workloads compile for the GPU actually present on first run, which needs make, a C++ compiler and the CUDA or ROCm toolkit installed on the host. Use --platform mock to exercise the tooling with no GPU at all.