Psych::SyntaxError couldn't parse YAML

Question

I am facing problem in rails application running on fedora 16 Rails version 2.3.5 and Ruby 1.9.2.p320 . The application running fine on Ubuntu 11.10. When I run the rails server and Hit any controller the following error in coming.

Psych::SyntaxError in controllername#actionname

couldn't parse YAML

I have tried the apply the following trick but it's not work for me.

I have added the following line in config/boot.rb

require 'yaml'

YAML::ENGINE.yamler = 'syck'

the error trace is

.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/psych.rb:148:in `parse'
.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/psych.rb:148:in `parse_stream'
.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/psych.rb:119:in `parse'
.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/psych.rb:106:in `load'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/activesupport-2.3.5/lib/active_support/vendor/i18n-0.1.3/lib/i18n/backend/simple.rb:189:in `load_yml'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/activesupport-2.3.5/lib/active_support/vendor/i18n-0.1.3/lib/i18n/backend/simple.rb:176:in `load_file'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/activesupport-.3.5/lib/active_support/vendor/i18n-0.1.3/lib/i18n/backend/simple.rb:13:in `block in load_translations'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/activesupport-2.3.5/lib/active_support/vendor/i18n-0.1.3/lib/i18n/backend/simple.rb:13:in `each'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/activesupport-2.3.5/lib/active_support/vendor/i18n-0.1.3/lib/i18n/backend/simple.rb:13:in `load_translations'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/activesupport-2.3.5/lib/active_support/vendor/i18n-0.1.3/lib/i18n/backend/simple.rb:85:in `init_translations'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/activesupport-2.3.5/lib/active_support/vendor/i18n-0.1.3/lib/i18n/backend/simple.rb:74:in `available_locales'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/activesupport-2.3.5/lib/active_support/vendor/i18n-0.1.3/lib/i18n.rb:50:in `available_locales'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/template.rb:226:in `valid_locale?'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/template.rb:243:in `parse_extensions'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/template.rb:233:in `split'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/template.rb:118:in `initialize'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/reloadable_template.rb:81:in `initialize'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/reloadable_template.rb:38:in `new'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/reloadable_template.rb:38:in `register_template_from_file'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/reloadable_template.rb:62:in `block in load_all_templates_from_dir'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/reloadable_template.rb:62:in `each'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/reloadable_template.rb:62:in `load_all_templates_from_dir'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/reloadable_template.rb:29:in `[]'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/paths.rb:48:in `block in find_template'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/paths.rb:47:in `each'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_view/paths.rb:47:in `find_template'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_controller/base.rb:1389:in `default_template'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_controller/base.rb:905:in `render'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:51:in `block in render_with_benchmark'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in `block in ms'
.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/benchmark.rb:310:in `realtime'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in `ms'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:51:in `render_with_benchmark'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_controller/base.rb:1326:in `default_render'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_controller/base.rb:1332:in `perform_action'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_controller/filters.rb:617:in `call_filters'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_controller/filters.rb:610:in `perform_action_with_filters'
/.rvm/gems/ruby-1.9.2-p320@sunago/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:68:in `block in perform_action_with_benchmark'
.rvm/gems/ruby-1.9.2-p320@sunago/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in `block in ms'
.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/benchmark.rb:310:in `realtime

Answer 1

Older YAML parsers did not like having tabs but only spaces. You might want to check your YAML file to see if it has any tabs at line 18. If this is the case, you might want to either fix your YAML files or upgrade the parser.