NationalSecurityAgency/ghidra · error · ValueError

min cannot exceed max

Error message

min cannot exceed max

What it means

Thrown by the Python ghidratrace Lifespan dataclass's __post_init__ when min > max, except for the special empty-span case (min == 0 and max == -1) which represents an empty Lifespan. A span where the lower bound exceeds the upper bound is logically invalid.

Source

Thrown at Ghidra/Debug/Debugger-rmi-trace/src/main/py/src/ghidratrace/client.py:120

        return self.max - self.min + 1


LIFESPAN_MIN = -1 << 63
LIFESPAN_MAX = (1 << 63) - 1


@dataclass(frozen=True)
class Lifespan:
    min: int = LIFESPAN_MIN
    max: int = LIFESPAN_MAX

    def __post_init__(self) -> None:
        if self.min < LIFESPAN_MIN:
            raise ValueError("min out of range of int64")
        if self.max > LIFESPAN_MAX:
            raise ValueError("max out of range of int64")
        if self.min > self.max and not (self.min == 0 and self.max == -1):
            raise ValueError("min cannot exceed max")

    def is_empty(self) -> bool:
        return self.min == 0 and self.max == -1

    def __str__(self) -> str:
        if self.is_empty():
            return "(EMPTY)"
        min = '(-inf' if self.min == LIFESPAN_MIN else f'[{self.min}'
        max = '+inf)' if self.max == LIFESPAN_MAX else f'{self.max}]'
        return f'{min},{max}'

    def __repr__(self) -> str:
        return 'Lifespan' + self.__str__()


@dataclass
class Schedule:
    """A more constrained form of TraceSchedule from our Java code.

View on GitHub (pinned to d5f144c24d)

Solutions

1. Order the bounds so min <= max when constructing, or use the explicit empty span Lifespan(0, -1) for empty.
2. If bounds may arrive in either order, normalize: mn, mx = sorted([a, b]).
3. Use the is_empty() idiom (0, -1) deliberately rather than passing an arbitrary inverted pair.

Example fix

# before
span = Lifespan(min=end_snap, max=start_snap)  # swapped

# after
mn, mx = min(start_snap, end_snap), max(start_snap, end_snap)
span = Lifespan(min=mn, max=mx)

mn, mx = min(start, end), max(start, end)
span = Lifespan(min=mn, max=mx)

def ordered(mn: int, mx: int) -> bool:
    return mn <= mx or (mn == 0 and mx == -1)

try:
    span = Lifespan(min=lo, max=hi)
except ValueError:
    lo, hi = min(lo, hi), max(lo, hi)
    span = Lifespan(min=lo, max=hi)

When it happens

Trigger: Constructing Lifespan(min=a, max=b) with a > b (and not the (0, -1) empty case), e.g. swapping min/max arguments or computing a range that inverted.

Common situations: Argument order swapped (max passed as min); start/end snaps computed such that start > end; off-by-one in schedule parsing producing an inverted range.

Related errors

• min out of range of int64
• max out of range of int64
• {object} is not {err_msg}
• No saved offers to launch {}
• Range [%s:%x+%x] entirely exceeds space min

AI-assisted analysis of NationalSecurityAgency/ghidra@d5f144c24d (2026-08-14). Data as JSON: /api/errors/e512a6cebd131b89. Report an issue: GitHub.