Test sp5_producer_unit_tests.rs:212 called `scratch_buf.len()` but `len` is declared as `pub len: usize` on MappedF32Buffer (mapped_pinned.rs:210), not a method. `cargo test --no-run` failed with E0599; library + cubin build was unaffected. One-character fix: `scratch_buf.len()` → `scratch_buf.len`. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>