See https://github.com/lukeroth/gdal/pull/102 for solution.

You can just modify the local "algorithms.go" by yourself.

    return CPLErr(C.GDALContourGenerate(
    src.cval,
    C.double(interval),
    C.double(base),
    C.int(len(fixedLevels)),
    fixedLevels_p,
    C.int(useNoDataValue),
    C.double(noDataValue),
    unsafe.Pointer(layer.cval),
    C.int(idFieldIndex),
    C.int(elevationFieldIndex),
    C.goGDALProgressFuncProxyB(),
    unsafe.Pointer(arg),
)).Err()

to

    cErr := C.GDALContourGenerate(
    src.cval,
    C.double(interval),
    C.double(base),
    C.int(len(fixedLevels)),
    fixedLevels_p,
    C.int(useNoDataValue),
    C.double(noDataValue),
    unsafe.Pointer(layer.cval),
    C.int(idFieldIndex),
    C.int(elevationFieldIndex),
    C.goGDALProgressFuncProxyB(),
    unsafe.Pointer(arg),
)
return CPLErrContainer{ErrVal: cErr}.Err()