The GPU experience collection kernels (dqn_experience_kernel.cu, ppo_experience_kernel.cu) use cudarc::nvrtc::compile_ptx() at runtime. Without libnvrtc.so the kernel compile fails silently and falls back to CPU experience collection. Adding cuda-nvrtc-12-4 (~30MB) enables full GPU-accelerated experience collection. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>