记一次BUG，RuntimeError: one of the variables needed for gradient computation has been modified by an inplace operation

错误：

RuntimeError: one of the variables needed for gradient computation has been modified by an inplace operation: [torch.cuda.FloatTensor [100, 1]], which is output 0 of TanhBackward0, is at version 1; expected version 0 instead. Hint: enable anomaly detection to find the operation that failed to compute its gradient, with torch.autograd.set_detect_anomaly(True).

场景：在训练pytorch网络的时候的报错。

解决方法：

mu *= 2
改为：
mu = mu * 2