Comfy-Org/ComfyUI · error · ValueError

len(args) should be 0, 1 or 2, but got {len(args)}

Error message

len(args) should be 0, 1 or 2, but got {len(args)}

What it means

Raised by the HyDiT _to_tuple_range helper used to build 2D positional-embedding grids: it accepts 0, 1, or 2 positional range arguments (start-only, start+stop, start+stop+num) and rejects anything else. It guards internal grid math, not user input.

Source

Thrown at comfy/ldm/hydit/posemb_layers.py:51

def get_meshgrid(start, *args):
    if len(args) == 0:
        # start is grid_size
        num = _to_tuple(start)
        start = (0, 0)
        stop = num
    elif len(args) == 1:
        # start is start, args[0] is stop, step is 1
        start = _to_tuple(start)
        stop = _to_tuple(args[0])
        num = (stop[0] - start[0], stop[1] - start[1])
    elif len(args) == 2:
        # start is start, args[0] is stop, args[1] is num
        start = _to_tuple(start)
        stop = _to_tuple(args[0])
        num = _to_tuple(args[1])
    else:
        raise ValueError(f"len(args) should be 0, 1 or 2, but got {len(args)}")

    grid_h = np.linspace(start[0], stop[0], num[0], endpoint=False, dtype=np.float32)
    grid_w = np.linspace(start[1], stop[1], num[1], endpoint=False, dtype=np.float32)
    grid = np.meshgrid(grid_w, grid_h)  # here w goes first
    grid = np.stack(grid, axis=0)   # [2, W, H]
    return grid

#################################################################################
#                   Sine/Cosine Positional Embedding Functions                  #
#################################################################################
# https://github.com/facebookresearch/mae/blob/main/util/pos_embed.py

def get_2d_sincos_pos_embed(embed_dim, start, *args, cls_token=False, extra_tokens=0):
    """
    grid_size: int of the grid height and width
    return:
    pos_embed: [grid_size*grid_size, embed_dim] or [1+grid_size*grid_size, embed_dim] (w/ or w/o cls_token)
    """

View on GitHub (pinned to 1c6d8d45b3)

Solutions

1. Call the helper with at most (stop) or (stop, num) positional args alongside start
2. Prefer the public calc_sizes/init_image_posemb wrappers instead of the low-level grid function
3. Check the function signature of the vendored posemb_layers version you are calling

Example fix

# before
grid = get_2d_rotary_pos_embed(dim, (start, stop, num))  # 3 args -> ValueError
# after
grid = get_2d_rotary_pos_embed(dim, stop, num)

assert len(args) <= 2, f"too many range args: {args}"

def valid_posemb_args(start, args) -> bool:
    return len(args) in (0, 1, 2)

When it happens

Trigger: Internal callers pass the wrong arity when computing get_fill_resize_and_crop sub_args for 'base' rope_img modes; externally reachable only through patched/misused code paths calling the helper directly with 3+ args.

Common situations: Monkey-patching or reusing posemb helpers with signatures from a different upstream version, or hand-rolling rope calls with extra arguments.

Related errors

• Unknown interpolation method {self.interpolation}
• Unknown rope_img: {rope_img}
• Got {params.axes_dim} but expected positional dim {pe_dim}
• Got {params.axes_dim} but expected positional dim {pe_dim}
• Unknown pos_emb_cls {self.pos_emb_cls}

AI-assisted analysis of Comfy-Org/ComfyUI@1c6d8d45b3 (2026-08-14). Data as JSON: /api/errors/6fe71ab7af1e96d0. Report an issue: GitHub.