ml-backtesting/build.rs reads FOXHUNT_CUDA_ARCH (defaults sm_86), ml-alpha/build.rs reads CUDA_COMPUTE_CAP. Template only set the latter, so lobsim cubins compiled for sm_86 on H100 (sm_90) → CUDA_ERROR_NO_BINARY_FOR_GPU at runtime. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>