transport.load_cpu

Always registers the Python-side Sinkhorn custom_ops; additionally loads the C++ ``exact_emd`` extension when a prebuilt ``.so`` is shipped in the wheel or a C++ toolchain is available for the JIT fallback. With ``TORCHMATCH_SKIP_TRANSPORT=1`` at build time and no toolchain at install, the extension is absent and EXACT_EMD fails with a targeted RuntimeError at call time; the Sinkhorn backends keep working. Set ``TORCHMATCH_DEBUG_LOADER=1`` to surface the underlying JIT failure when diagnosing a partially-broken extension.