Lack of help if coverage too large

[guisalmon]

Code :

import logging
from landez import MBTilesBuilder
from landez import TilesManager


logging.basicConfig(level=logging.DEBUG)

mb = MBTilesBuilder(mbtiles_file="/home/guillaume/Tiles/Merge/tiles.mbtiles",
                    cache=True, filepath="/home/guillaume/Tiles/Merge/merged.mbtiles")
overlay = TilesManager(mbtiles_file="/home/guillaume/Tiles/Merge/tiles_kml_v3.mbtiles")
mb.add_layer(overlay)
mb.add_coverage(bbox=(5.0826,42.4397,5.6940,43.2806),
                zoomlevels=range(10,18))
mb.run()

Error :

WARNING:landez.tiles:Could not extract tile (15, 16858, 12044) from /home/guillaume/Tiles/Merge/tiles_kml_v3.mbtiles
DEBUG:landez.cache:Save 857 bytes to /tmp/landez/tilesmbtilestileskmlv3mbtiles10/15/16858/20723.png
DEBUG:landez.sources:Extract tile (16, 33704, 24120)
DEBUG:landez.sources:Execute query 'SELECT tile_data FROM tiles WHERE zoom_level=? AND tile_column=? AND tile_row=?;' ((16, 33704, 41415),)
Traceback (most recent call last):
File "merge_tiles.py", line 14, in
mb.run()
File "/usr/local/lib/python2.7/dist-packages/landez-2.0.4.dev0-py2.7.egg/landez/tiles.py", line 293, in run
self._gather((z, x, y))
File "/usr/local/lib/python2.7/dist-packages/landez-2.0.4.dev0-py2.7.egg/landez/tiles.py", line 327, in gather
tilecontent = self.tile((z, x, y))
File "/usr/local/lib/python2.7/dist-packages/landez-2.0.4.dev0-py2.7.egg/landez/tiles.py", line 160, in tile
output = self.reader.tile(z, x, y)
File "/usr/local/lib/python2.7/dist-packages/landez-2.0.4.dev0-py2.7.egg/landez/sources.py", line 96, in tile
raise ExtractionError(("Could not extract tile %s from %s") % ((z, x, y), self.filename))
landez.sources.ExtractionError: Could not extract tile (16, 33704, 24120) from /home/guillaume/Tiles/Merge/tiles.mbtiles