trsfm = transforms.Compose([
            transforms.Resize((32, 32)),
            transforms.ToTensor(),
            transforms.Normalize((0.1307,), (0.3081,)),
            transforms.Lambda(lambda x: x.repeat(3, 1, 1))
            ])

Should become
        def tmp_func(x):
            return x.repeat(3, 1, 1)

        trsfm = transforms.Compose([
            transforms.Resize((32, 32)),
            transforms.ToTensor(),
            transforms.Normalize((0.1307,), (0.3081,)),
            transforms.Lambda(tmp_func)
            ])