print statement causes inplace error #99968
Description
🐛 Describe the bug
Reported in: https://discuss.pytorch.org/t/error-with-view-no-grad-and-inplace-modify/173082
but I couldn't find the created GitHub issue and the author didn't follow up.
Code to reproduce the issue:
net = nn.Sequential(
nn.Linear(10, 10),
nn.ReLU(),
nn.Linear(10, 10),
nn.ReLU(),
nn.Linear(10, 10),
nn.ReLU(),
)
with torch.no_grad():
for param in net.parameters():
for j in param.flatten():
#print("current j", j)
j += 1Comment the print statement in and the code will fail with:
RuntimeError: A view was created in no_grad mode and its base or another view of its base has been modified inplace with grad mode enabled. Given that this use case is ambiguous and error-prone, it is forbidden. You can clarify your code by moving both the view and the inplace either both inside the no_grad block (if you don't want the inplace to be tracked) or both outside (if you want the inplace to be tracked).I would assume the inplace operation is allowed as it's in a no_grad block and no computation graph was ever created.
Also, maybe related to: https://discuss.pytorch.org/t/old-problem-but-strange-things-trying-to-backward-through-the-graph-a-second-time/178369
but no executable code snippet was posted yet.
Versions
Reproduced in a nightly build: 2.1.0.dev20230407+cu118.
CC @albanD as we talked about this issue before.
cc @ezyang @gchanan @zou3519 @kadeng @albanD @gqchen @pearu @nikitaved @soulitzer @lezcano @Varal7