【发布时间】：2013-12-20 22:56:58
【问题描述】：
我尝试安装this dashing widget，运行dashing start时出现以下错误
/var/lib/gems/1.9.1/gems/dashing-1.3.1/lib/dashing.rb:26:in `block (2 levels) in <top (required)>': undefined method `history' for Sinatra::Application:Class (NoMethodError)
然后我删除了这个新小部件的所有方面（它在 /widgets 目录中的文件夹、它的作业 .rb 文件和 .erb 文件中的代码）。但是，此错误仍然存在，我什至无法启动仪表板。这对我来说是个大问题。有人可以帮帮我吗？
编辑：
完整的错误是
/var/lib/gems/1.9.1/gems/dashing-1.3.1/lib/dashing.rb:26:in `block (2 levels) in <top (required)>': undefined method `history' for Sinatra::Application:Class (NoMethodError)
from /var/lib/gems/1.9.1/gems/dashing-1.3.1/lib/dashing.rb:25:in `open'
from /var/lib/gems/1.9.1/gems/dashing-1.3.1/lib/dashing.rb:25:in `block in <top (required)>'
/usr/lib/ruby/1.9.1/psych.rb:203:in `parse': (history.yml): control characters are not allowed at line 1 column 1 (Psych::SyntaxError)
from /usr/lib/ruby/1.9.1/psych.rb:203:in `parse_stream'
from /usr/lib/ruby/1.9.1/psych.rb:151:in `parse'
from /usr/lib/ruby/1.9.1/psych.rb:127:in `load'
from /usr/lib/ruby/1.9.1/psych.rb:297:in `block in load_file'
from /usr/lib/ruby/1.9.1/psych.rb:297:in `open'
from /usr/lib/ruby/1.9.1/psych.rb:297:in `load_file'
from /var/lib/gems/1.9.1/gems/dashing-1.3.1/lib/dashing.rb:31:in `<top (required)>'
from config.ru:2:in `require'
from config.ru:2:in `block in <main>'
from /var/lib/gems/1.9.1/gems/rack-1.5.2/lib/rack/builder.rb:55:in `instance_eval'
from /var/lib/gems/1.9.1/gems/rack-1.5.2/lib/rack/builder.rb:55:in `initialize'
from config.ru:1:in `new'
from config.ru:1:in `<main>'
from /var/lib/gems/1.9.1/gems/thin-1.6.1/lib/rack/adapter/loader.rb:33:in `eval'
from /var/lib/gems/1.9.1/gems/thin-1.6.1/lib/rack/adapter/loader.rb:33:in `load'
from /var/lib/gems/1.9.1/gems/thin-1.6.1/lib/thin/controllers/controller.rb:182:in `load_rackup_config'
from /var/lib/gems/1.9.1/gems/thin-1.6.1/lib/thin/controllers/controller.rb:72:in `start'
from /var/lib/gems/1.9.1/gems/thin-1.6.1/lib/thin/runner.rb:200:in `run_command'
from /var/lib/gems/1.9.1/gems/thin-1.6.1/lib/thin/runner.rb:156:in `run!'
from /var/lib/gems/1.9.1/gems/thin-1.6.1/bin/thin:6:in `<top (required)>'
from /usr/local/bin/thin:23:in `load'
from /usr/local/bin/thin:23:in `<main>'
【问题讨论】：
-
检查堆栈跟踪，而不仅仅是这一行，看看它在哪里被调用。
-
我已经包含了完整的错误信息
-
我的 psych.rb 文件似乎有问题
-
也许它试图解析的 YAML 文件有错误？
-
history.yml 是空的。是这个问题吗？