sgl-project/sglang · error · ValueError

{rope_type=} not supported. Choose between 'interleaved' and

Error message

{rope_type=} not supported. Choose between 'interleaved' and 'split'.

What it means

ValueError from the LTX-2 rotary embedding __init__: rope_type must be exactly 'interleaved' or 'split'. Any other string (typos, 'default', 'linear') is rejected at construction time.

Source

Thrown at python/sglang/multimodal_gen/runtime/models/adapter/ltx_2_connector.py:237

class LTX2RotaryPosEmbed1d(nn.Module):
    """
    1D rotary positional embeddings (RoPE) for the LTX 2.0 text encoder connectors.
    """

    def __init__(
        self,
        dim: int,
        base_seq_len: int = 4096,
        theta: float = 10000.0,
        double_precision: bool = True,
        rope_type: str = "interleaved",
        num_attention_heads: int = 32,
    ):
        super().__init__()
        if rope_type not in ["interleaved", "split"]:
            raise ValueError(
                f"{rope_type=} not supported. Choose between 'interleaved' and 'split'."
            )

        self.dim = dim
        self.base_seq_len = base_seq_len
        self.theta = theta
        self.double_precision = double_precision
        self.rope_type = rope_type
        self.num_attention_heads = num_attention_heads

    def forward(
        self,
        batch_size: int,
        pos: int,
        device: Union[str, torch.device],
        dtype: Optional[torch.dtype] = None,
    ) -> Tuple[torch.Tensor, torch.Tensor]:
        # 1. Get 1D position ids

View on GitHub (pinned to 0132848349)

Solutions

1. Use exactly 'interleaved' or 'split'
2. Normalize incoming config: rope_type.strip().lower() and map known aliases before passing
3. Validate config values at load time with a clear error

Example fix

// before
rope_type="Interleaved"
// after
rope_type="interleaved"

rope_type = rope_type.strip().lower()
assert rope_type in {"interleaved", "split"}, rope_type

def is_valid_rope_type(v: str) -> TypeGuard[str]:
    return isinstance(v, str) and v in {"interleaved", "split"}

When it happens

Trigger: Constructing the rotary module with rope_type='half'/'rope'/'interleaved ' (typo/case/whitespace) or a value ported from another codebase's naming scheme.

Common situations: Converting configs from other video-model repos that use different rope naming; case sensitivity ('Interleaved'); trailing whitespace from config parsing.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• Expected x.shape[-1] to be even for split rotary, got {last}
• head_dim must be a multiple of 8, got {head_dim}.
• num_frames/height/width must be provided for RoPE coordinate
• audio_num_frames must be provided for RoPE coordinate genera
• rope_pool_fused expects q/k/v to be 3-D

AI-assisted analysis of sgl-project/sglang@0132848349 (2026-08-28). Data as JSON: /api/errors/8e1557cca2bfa011. Report an issue: GitHub.