fix: disable spatial_correlation_sampler, use pure-PyTorch fallback

The C++ extension cannot compile on ZeroGPU (PyTorch 2.10 / CUDA 12.8+
dispatch macro incompatibility + CUDA version mismatch).

model/attention.py already has a pure-PyTorch path (pad_and_unfold)
when enable_corr=False. Set all 3 defaults to False and remove
the install machinery from app.py.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app.py

@@ -232,70 +232,9 @@ def build_args_list_for_test(d16_batch_path: str,
             args.extend([flag, str(v)])
     return args
 
-# ===== ZeroGPU: install spatial-correlation-sampler at runtime =====
-
-def ensure_correlation_extension_installed():
-    """Install spatial_correlation_sampler at runtime inside @spaces.GPU where CUDA is live."""
-    try:
-        import spatial_correlation_sampler
-        return
-    except ImportError:
-        pass
-
-    import torch
-    cuda_home = os.environ.get("CUDA_HOME", "")
-    nvcc_ok = shutil.which("nvcc") is not None
-    diag = (f"torch={torch.__version__}, cuda={torch.version.cuda}, "
-            f"torch.cuda.avail={torch.cuda.is_available()}, "
-            f"CUDA_HOME={cuda_home!r}, nvcc={nvcc_ok}")
-    print(f"[DEBUG] {diag}")
-    # Store diagnostics for error reporting
-    _diag_info = diag
-
-    # Ensure CUDA_HOME is set so setuptools can find nvcc
-    if not cuda_home:
-        for candidate in ["/usr/local/cuda", "/usr/lib/cuda", "/opt/cuda"]:
-            if path.isdir(candidate):
-                os.environ["CUDA_HOME"] = candidate
-                print(f"[INFO] Set CUDA_HOME={candidate}")
-                break
-
-    # Also make sure nvcc is in PATH
-    cuda_home = os.environ.get("CUDA_HOME", "")
-    if cuda_home and not nvcc_ok:
-        cuda_bin = path.join(cuda_home, "bin")
-        if path.isdir(cuda_bin):
-            os.environ["PATH"] = cuda_bin + ":" + os.environ.get("PATH", "")
-            print(f"[INFO] Added {cuda_bin} to PATH")
-
-    print("[INFO] Installing spatial-correlation-sampler from git source...")
-    result = subprocess.run(
-        [sys.executable, "-m", "pip", "install", "--no-build-isolation",
-         "git+https://github.com/ClementPinard/Pytorch-Correlation-extension.git"],
-        capture_output=True, text=True, timeout=120,
-        env={**os.environ},
-    )
-    if result.returncode != 0:
-        print(f"[WARN] pip install from git failed (rc={result.returncode})")
-        print(f"[WARN] stderr tail: {result.stderr[-1500:]}")
-        # Fallback: try PyPI package
-        print("[INFO] Trying pip install spatial-correlation-sampler from PyPI...")
-        result2 = subprocess.run(
-            [sys.executable, "-m", "pip", "install", "spatial-correlation-sampler"],
-            capture_output=True, text=True, timeout=120,
-            env={**os.environ},
-        )
-        if result2.returncode != 0:
-            raise RuntimeError(
-                f"Cannot install spatial-correlation-sampler.\n"
-                f"Diag: {_diag_info}\n"
-                f"Git stderr:\n{result.stderr[-2000:]}\n"
-                f"PyPI stderr:\n{result2.stderr[-2000:]}"
-            )
-
-    importlib.invalidate_caches()
-    import spatial_correlation_sampler  # noqa: F811
-    print("[INFO] spatial-correlation-sampler installed successfully.")
+# ===== spatial_correlation_sampler: DISABLED =====
+# The C++ extension is incompatible with PyTorch 2.10 / CUDA 12.8+ on ZeroGPU.
+# model/attention.py now uses enable_corr=False (pure-PyTorch fallback).
 
 # ----------------- GRADIO HANDLER -----------------
 
@@ -308,13 +247,6 @@ def gradio_infer(
     num_proto, top_k, mem_every, deep_update,
     save_scores, flip, size, reverse
 ):
-    # <<< ZeroGPU 分配后：按需安装 Pytorch-Correlation-extension >>>
-    try:
-        ensure_correlation_extension_installed()
-    except Exception as install_err:
-        return None, f"spatial-correlation-sampler install failed:\n{install_err}"
-    # --------------------------------------------------------------
-
     # 1) 基本校验与临时目录
     if bw_video is None:
         return None, "请上传黑白视频 / Please upload a B&W video."

model/attention.py

@@ -130,7 +130,7 @@ class MultiheadLocalAttentionV1(nn.Module):
                  max_dis=7,
                  dilation=1,
                  use_linear=True,
-                 enable_corr=True):
+                 enable_corr=False):
         super().__init__()
         self.dilation = dilation
         self.window_size = 2 * max_dis + 1
@@ -248,7 +248,7 @@ class MultiheadLocalAttentionV2(nn.Module):
                  max_dis=7,
                  dilation=1,
                  use_linear=True,
-                 enable_corr=True,
+                 enable_corr=False,
                  d_att=None,
                  use_dis=False):
         super().__init__()
@@ -721,7 +721,7 @@ class LocalGatedPropagation(nn.Module):
                  max_dis=7,
                  dilation=1,
                  use_linear=True,
-                 enable_corr=True,
+                 enable_corr=False,
                  d_att=None,
                  use_dis=False,
                  expand_ratio=2.):