sgl-project/sglang · error · ValueError

target.aspect_ratio components must be positive, got {value!

Error message

target.aspect_ratio components must be positive, got {value!r}

What it means

Both integer components of target.aspect_ratio must be strictly positive. A parseable pair like '0:9' or '-16:9' fails this check because a zero/negative dimension is meaningless.

Source

Thrown at python/sglang/multimodal_gen/runtime/pipelines_core/stages/model_specific_stages/minimax_h3/resolved_plan.py:90

    default_audio_flow_shift: float
    flow_shift: float | None
    audio_flow_shift: float | None
    shape: dict
    condition_mask: dict


def _parse_aspect_ratio(value: str) -> tuple[int, int]:
    parts = value.split(":")
    if len(parts) != 2:
        raise ValueError(f"target.aspect_ratio must be 'W:H' or 'auto', got {value!r}")
    try:
        w, h = int(parts[0]), int(parts[1])
    except ValueError as exc:
        raise ValueError(
            f"target.aspect_ratio must be integer 'W:H', got {value!r}"
        ) from exc
    if w <= 0 or h <= 0:
        raise ValueError(
            f"target.aspect_ratio components must be positive, got {value!r}"
        )
    return w, h


def _nearest_multiple(value: float, multiple: int) -> int:
    return max(multiple, int(round(float(value) / multiple)) * multiple)


def _validate_base_short_edge(value: Any) -> int:
    try:
        short_edge = int(value)
    except (TypeError, ValueError) as exc:
        raise ValueError(
            f"target.short_edge must be an integer, got {value!r}"
        ) from exc
    if short_edge != value or short_edge <= 0:
        raise ValueError(f"target.short_edge must be a positive integer, got {value!r}")

View on GitHub (pinned to 0132848349)

Solutions

Fix the upstream computation so neither component is zero/negative
Guard with a fallback like '1:1' when computed ratios are degenerate

Example fix

# before
aspect = f"{w}:{h}"  # w==0
# after
aspect = f"{w or 1}:{h or 1}"

Defensive patterns

Strategy: validation

Validate before calling

def parts_positive(v):
    try: w, h = v.split(":"); return int(w) > 0 and int(h) > 0
    except Exception: return False

Type guard

def is_positive_ratio(v) -> bool:
    try:
        w, h = v.split(":"); return int(w) > 0 and int(h) > 0
    except Exception:
        return False

Try / catch

null

Prevention

Guard zero-dimension probes before formatting the ratio

When it happens

Trigger: Calling minimax_h3_resolve_plan with target.aspect_ratio such as '0:9', '-1:1', or computed values where one side evaluates to 0.

Common situations: Aspect ratio computed from a zero width/height upstream (e.g. failed probe defaults to 0) and rendered as '0:0'.

Related errors

AI-assisted analysis of sgl-project/sglang@0132848349 (2026-08-28). Data as JSON: /api/errors/e1f62073e2d0523e. Report an issue: GitHub.