http://mapbox.com/tilemill/docs/guides/osm-bright-ubuntu-quickstart/

gistfile1.txt

rub21@ubuntu:~$ imposm -U postgres -d dblima ~/Downloads/mapbox-osm-bright-affc8b6/imposm-mapping.py  --read --write --optimize --deploy-production-tables ~/Downloads/lima.osm.pbf --merge-cache
password for postgres at localhost:
[12:46:43] ## reading /home/rub21/Downloads/mapbox-osm-bright-affc8b6/imposm-mapping.py
[12:46:43] coords: 233k nodes: 4k ways: 33k relations: 0k (estimated)
Traceback (most recent call last):
  File "/usr/local/bin/imposm", line 9, in <module>
    load_entry_point('imposm==2.4.0', 'console_scripts', 'imposm')()
  File "/usr/local/lib/python2.7/dist-packages/imposm/app.py", line 222, in main
    reader.read(arg)
  File "/usr/local/lib/python2.7/dist-packages/imposm/reader.py", line 88, in read
    parser.parse(filename)
  File "/usr/local/lib/python2.7/dist-packages/imposm/parser/simple.py", line 66, in parse
    raise NotImplementedError('unknown file extension')
NotImplementedError: unknown file extension