Rasterio Tiling (broken)

import rasterio
from rasterio.transform import from_bounds as transform_from_bounds
from rasterio.warp import reproject, transform_bounds
from rasterio.windows import transform as window_transform

with rasterio.open(source_path) as src:
    tile_bounds_src_crs = transform_bounds(dst_srs, src.crs, *tile_bounds)
    tile_window = src.window(*tile_bounds_src_crs)
    tile_data = src.read(window=tile_window)

    # translate the values into the desired range
    if scaled_min_max_pixel_values:
        for i, scaled_vals in enumerate(scaled_min_max_pixel_values):
            try:
                tile_data[i] = numpy.interp(tile_data[i],
                                            [tile_data[i].min(), tile_data[i].max()],
                                            scaled_vals)
            except IndexError:
                self.logger.warn('Too many scaled_min_max_values passed')

    kwds = {
        'transform': transform_from_bounds(*tile_bounds, tile_size, tile_size),
        'driver': 'PNG',
        'dtype': 'uint8',
        'height': tile_size,
        'width': tile_size,
        'crs': dst_srs,
        'count': src.count + 1
    }

    # create the output directory
    os.makedirs(os.path.dirname(output_path), exist_ok=True)

    with rasterio.open(output_path, 'w', **kwds) as dst:
        for i in range(1, src.count + 1):
            reproject_args = {
                'source': tile_data[i-1],
                'src_crs': src.crs,
                'src_transform': window_transform(tile_window, src.transform),
                'destination': rasterio.band(dst, i),
                'resampling': self._get_resample_alg_value(resample_alg),
                'dst_alpha': src.count + i
            }

            # can only specify nan nodata value on float32 and float64 input bands
            if src.dtypes[i-1].startswith('float'):
                reproject_args['src_nodata'] = numpy.nan

            reproject(**reproject_args)