pathwaycom/pathway · error · ValueError

Fields of type {column_type.typehint} are not supported in c

Error message

Fields of type {column_type.typehint} are not supported in connector groups

What it means

Error "Fields of type {column_type.typehint} are not supported in connector groups" thrown in pathwaycom/pathway.

Source

Thrown at python/pathway/io/_synchronization.py:314

        if not is_table_found:
            raise ValueError(
                "Only unchanged columns of an input tables can be used in input synchronization groups"
            )

    if len(column_types) > 1:
        raise ValueError(
            "All synchronization group column types must coincide. "
            "However several types have been detected: {}".format(
                ", ".join(sorted([f"'{t}'" for t in column_types]))
            )
        )


def _check_column_type(column, max_difference):
    column_type = column._column.dtype
    if column_type not in _SUPPORTED_COLUMN_DTYPES:
        raise ValueError(
            f"Fields of type {column_type.typehint} are not supported in connector groups"
        )
    if isinstance(max_difference, int) and column_type != dtype.INT:
        raise ValueError(
            "If max_difference is an integer value, the values of a column must have a type of "
            f"int. However, the column '{column}' has type '{column_type.typehint}'"
        )
    if isinstance(max_difference, datetime.timedelta) and column_type not in (
        dtype.DATE_TIME_NAIVE,
        dtype.DATE_TIME_UTC,
        dtype.DURATION,
    ):
        raise ValueError(
            "If max_difference is a Duration, the values of a column must either have a type of "
            f"DateTimeUtc, DateTimeNaive or Duration. However, the column '{column}' "
            f"has type '{column_type.typehint}'"
        )

View on GitHub (pinned to fa2f74a464)

Solutions

1. Use connector group columns of a supported scalar type (int, float, Duration, DateTimeNaive, DateTimeUtc); convert unsupported types (e.g. list, Json) before registering the group.

Example fix

pw.io.register_input_synchronization_group(pw.declare_type(int, t.ts))

When it happens

Trigger: Thrown at python/pathway/io/_synchronization.py:314 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of pathwaycom/pathway@fa2f74a464 (2026-08-15). Data as JSON: /api/errors/68cebecaee3a5b86. Report an issue: GitHub.