Debugging ColBERT Index Differences Between PyTorch 2.7.1 and 2.8.0

Background I’ve been redoing my colbert-ai index comparisons between PyTorch versions using bitsandbytes’ torch.allclose tolerances . There are three PyTorch version changes that cause index artifact changes: 2.0.1 to 2.1.0 ( BertModel forward pass outputs diverge for all inputs ), 2.4.1 to 2.5.0 ( certain batch sizes cause BertModel output divergence ), and 2.7.1 to 2.8.0 (detailed in this blog…