Per pearl_build_rs_rerun_if_env_changed, every std::env::var() must be
paired with cargo:rerun-if-env-changed. Task #321 fixed crates/ml/build.rs
(commit e3d082968) but missed 6 sibling build.rs files. Each reads
CUDA_COMPUTE_CAP without registering the rerun directive, so cargo
sees no env-change between e.g. SM 89 (L40S) → SM 90 (H100) workflow
re-submissions and cache-hits the wrong-arch cubin from the previous
run. At runtime, the H100 fails to load the SM 89 cubin with
CUDA_ERROR_NO_BINARY_FOR_GPU on rmsnorm — exactly what killed
train-multi-seed-vlv8c (commit 0371d6a76, post-Class-B chain).
Files (all add `println!("cargo:rerun-if-env-changed=CUDA_COMPUTE_CAP")`
just before the env::var() read):
- crates/ml-dqn/build.rs (rmsnorm — root cause of vlv8c failure)
- crates/ml-ensemble/build.rs
- crates/ml-explainability/build.rs
- crates/ml-ppo/build.rs
- crates/ml-supervised/build.rs
- crates/ml-core/build.rs
Atomic single commit per feedback_no_partial_refactor.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
- New ensemble_reduce_kernel.cu: fused sigmoid→mean→weighted-sum in
one kernel, single block, thread-per-model. Pure f32, no bf16.
- build.rs: nvcc compilation without --use_fast_math
- aggregate_logits_gpu: loads cubin, uploads raw f32 buffers, launches
kernel, reads back single scalar. No GpuTensor/ActivationKernels.
- Removed aggregate_logits_cpu (dead code, GPU-only system)
- ml-explainability: removed unreachable dead code after stub return,
prefixed unused vars. Zero warnings.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
