Error in gtfs_2_sqlite

[kalon33]

Hello, I've an error when running gtfs_2_sqlite:

nicolas@spiralo2:~/transports/GTFS-viz$ rake parse:gtfs_2_sqlite --trace
** Invoke parse:gtfs_2_sqlite (first_time)
** Execute parse:gtfs_2_sqlite
14:48:54 +0 : START SQL inserts from GTFS files
rm -f /home/nicolas/transports/GTFS-viz/tmp/TAG/gtfs.db
14:48:54 +0 : SQL INSERT calendar, 16 records
14:48:54 +0 : SQL INSERT routes, 13 records
14:48:54 +0 : SQL INSERT stop_times, 158699 records
rake aborted!
NoMethodError: undefined method length' for nil:NilClass /home/nicolas/transports/GTFS-viz/inc/gtfs.rb:345:invalidate_time'
/home/nicolas/transports/GTFS-viz/inc/gtfs.rb:70:in block in gtfs_to_sqlite' /home/nicolas/transports/GTFS-viz/inc/gtfs.rb:65:ineach'
/home/nicolas/transports/GTFS-viz/inc/gtfs.rb:65:in gtfs_to_sqlite' /home/nicolas/transports/GTFS-viz/inc/gtfs.rb:47:inblock in parse_file'
/home/nicolas/transports/GTFS-viz/inc/gtfs.rb:38:in foreach' /home/nicolas/transports/GTFS-viz/inc/gtfs.rb:38:inparse_file'
/home/nicolas/transports/GTFS-viz/Rakefile:77:in block (3 levels) in <top (required)>' /home/nicolas/transports/GTFS-viz/Rakefile:68:ineach'
/home/nicolas/transports/GTFS-viz/Rakefile:68:in block (2 levels) in <top (required)>' /var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/task.rb:240:incall'
/var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/task.rb:240:in block in execute' /var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/task.rb:235:ineach'
/var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/task.rb:235:in execute' /var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/task.rb:179:inblock in invoke_with_call_chain'
/usr/lib/ruby/1.9.1/monitor.rb:211:in mon_synchronize' /var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/task.rb:172:ininvoke_with_call_chain'
/var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/task.rb:165:in invoke' /var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/application.rb:150:ininvoke_task'
/var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/application.rb:106:in block (2 levels) in top_level' /var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/application.rb:106:ineach'
/var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/application.rb:106:in block in top_level' /var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/application.rb:115:inrun_with_threads'
/var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/application.rb:100:in top_level' /var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/application.rb:78:inblock in run'
/var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/application.rb:176:in standard_exception_handling' /var/lib/gems/1.9.1/gems/rake-10.3.2/lib/rake/application.rb:75:inrun'
/var/lib/gems/1.9.1/gems/rake-10.3.2/bin/rake:33:in <top (required)>' /usr/local/bin/rake:23:inload'
/usr/local/bin/rake:23:in `

'
Tasks: TOP => parse:gtfs_2_sqlite

What's the problem?