[FIX] Use materialize_grad=True in GGNVPs

backpack/hessianfree/lop.py

@@ -13,6 +13,7 @@ def L_op(ys, xs, ws, retain_graph=True, detach=True):
         create_graph=True,
         retain_graph=retain_graph,
         allow_unused=True,
+        materialize_grads=True,
     )
     if detach:
         return tuple(j.detach() for j in vJ)

backpack/hessianfree/rop.py

@@ -18,10 +18,17 @@ def R_op(ys, xs, vs, retain_graph=True, detach=True):
         create_graph=True,
         retain_graph=retain_graph,
         allow_unused=True,
+        materialize_grads=True,
     )
 
     re = torch.autograd.grad(
-        gs, ws, grad_outputs=vs, create_graph=True, retain_graph=True, allow_unused=True
+        gs,
+        ws,
+        grad_outputs=vs,
+        create_graph=True,
+        retain_graph=True,
+        allow_unused=True,
+        materialize_grads=True,
     )
 
     if detach:

setup.cfg

@@ -34,7 +34,7 @@ setup_requires =
   setuptools_scm
 # Dependencies of the project (semicolon/line-separated):
 install_requires =
-    torch >= 1.9.0
+    torch >= 2.2.0
     torchvision >= 0.7.0
     einops >= 0.3.0, < 1.0.0
     unfoldNd >= 0.2.0, < 1.0.0