Ruby on rails 3 prawn未定义的方法头

我正在尝试将我的cucumber测试输出为pdf格式。我做这个已经有一段时间了，而且很有效。升级某些gems后，我的pdf输出已停止工作，出现以下错误：

% rake cucumber:new_report_pdf                             
(in /home/map7/pais)
NOTICE:  CREATE TABLE will create implicit sequence "employees_id_seq" for serial column "employees.id"
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "employees_pkey" for table "employees"
NOTICE:  CREATE TABLE will create implicit sequence "entities_id_seq" for serial column "entities.id"
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "entities_pkey" for table "entities"
NOTICE:  CREATE TABLE will create implicit sequence "ledgers_id_seq" for serial column "ledgers.id"
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "ledgers_pkey" for table "ledgers"
NOTICE:  CREATE TABLE will create implicit sequence "staff_id_seq" for serial column "staff.id"
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "staff_pkey" for table "staff"
bundle exec /home/map7/.rvm/rubies/ruby-1.9.2-p180/bin/ruby -I "/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib:lib" "/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/bin/cucumber"  --profile new_report_pdf
Using the new_report_pdf profile...
..........undefined method `headers=' for #<Prawn::Table:0x0000000697d4d8> (NoMethodError)
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/prawn-0.11.1/lib/prawn/table.rb:124:in `block in initialize'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/prawn-0.11.1/lib/prawn/table.rb:124:in `each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/prawn-0.11.1/lib/prawn/table.rb:124:in `initialize'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/prawn-0.11.1/lib/prawn/table.rb:25:in `new'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/prawn-0.11.1/lib/prawn/table.rb:25:in `table'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:240:in `print_table'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:161:in `block in before_multiline_arg'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:219:in `call'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:219:in `block in render'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:218:in `each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:218:in `render'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:229:in `flush'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:105:in `after_feature_element'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_walker.rb:174:in `block in send_to_all'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_walker.rb:172:in `each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_walker.rb:172:in `send_to_all'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_walker.rb:165:in `broadcast'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_walker.rb:50:in `visit_feature_element'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/feature.rb:40:in `block in accept'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/feature.rb:39:in `each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/feature.rb:39:in `accept'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_walker.rb:20:in `block in visit_feature'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_walker.rb:164:in `broadcast'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_walker.rb:19:in `visit_feature'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/features.rb:29:in `block in accept'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/features.rb:17:in `each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/features.rb:17:in `each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/features.rb:28:in `accept'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_walker.rb:14:in `block in visit_features'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_walker.rb:164:in `broadcast'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_walker.rb:13:in `visit_features'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/runtime.rb:45:in `run!'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/cli/main.rb:43:in `execute!'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/cli/main.rb:20:in `execute'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/bin/cucumber:14:in `<main>'
rake aborted!
Command failed with status (1): [bundle exec /home/map7/.rvm/rubies/ruby-1....]

(See full trace by running task with --trace)

%rake cumber:new\u report\u pdf
（in/home/map7/pais）
注意：创建表将为序列列“employees.id”创建隐式序列“employees\u id\u seq”
注意：CREATE TABLE/主键将为表employees创建隐式索引employees\u pkey
注意：CREATE TABLE将为序列列“entities.id”创建隐式序列“entities\u id\u seq”
注意：CREATE TABLE/主键将为表“entities”创建隐式索引“entities\u pkey”
注意：创建表将为序列列“ledgers.id”创建隐式序列“ledgers\u id\u seq”
注意：CREATE TABLE/主键将为表“账本”创建隐式索引“账本”
注意：CREATE TABLE将为序列列“staff.id”创建隐式序列“staff\u id\u seq”
注意：CREATE TABLE/主键将为表“staff”创建隐式索引“staff_pkey”
bundle exec/home/map7/.rvm/rubies/ruby-1.9.2-p180/bin/ruby-I“/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib:lib”“/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cumber-0.10.2/bin/cumber”--配置文件新报告
正在使用新的\u报告\u pdf配置文件。。。
…….未定义的方法“headers=”表示#（NoMethodError）
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/prawn-0.11.1/lib/prawn/table.rb:124:在“初始化中的块”中
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/prawn-0.11.1/lib/prawn/table.rb:124:in'each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/prawn-0.11.1/lib/prawn/table.rb:124:在“初始化”中
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/prawn-0.11.1/lib/prawn/table.rb:25:in'new'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/prawn-0.11.1/lib/prawn/table.rb:25:in“table”
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:240:in'print_table'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:161:in `在多行参数之前块入'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:219:in'call'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:219:in“渲染中的块”
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:218:in'each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:218:in'render'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:229:in'flush'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/formatter/pdf.rb:105:in“after\u feature\u element”
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree\u walker.rb:174:in“block in send\u to\u all”
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_-walker.rb:172:in'each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree\u walker.rb:172:“发送给所有人”
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_-walker.rb:165:在“广播”中
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree\u walker.rb:50:在“访问”功能元素中
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/feature.rb:40:在“接受中的块”中
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/feature.rb:39:in'each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/feature.rb:39:in'accept'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree\u walker.rb:20:在“访问中的块”功能中
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_-walker.rb:164:in“广播”
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree\u walker.rb:19:在“访问”功能中
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/features.rb:29:在“接受中的块”中
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/features.rb:17:in'each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/features.rb:17:in'each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/features.rb:28:in'accept'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree\u walker.rb:14:在“访问功能中的块”中
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree_-walker.rb:164:in“广播”
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/ast/tree\u walker.rb:13:in“访问”功能
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/runtime.rb:45:in'run！'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/cli/main.rb:43:in'execute！'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/lib/cucumber/cli/main.rb:20:in'execute'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-0.10.2/bin/cucumber:14:in`'
雷克流产了！
命令失败，状态为（1）：[bundle exec/home/map7/.rvm/rubies/ruby-1….]
（通过使用--trace运行任务查看完整跟踪）

这是我的cucumber.yml文件

<%
rerun = File.file?('rerun.txt') ? IO.read('rerun.txt') : ""
rerun_opts = rerun.to_s.strip.empty? ? "--format #{ENV['CUCUMBER_FORMAT'] || 'progress'} features" : "--format #{ENV['CUCUMBER_FORMAT'] || 'pretty'} #{rerun}"
std_opts = "--format #{ENV['CUCUMBER_FORMAT'] || 'progress'} --strict --tags ~@wip"
%>
default: <%= std_opts %> features
wip: --tags @wip:3 --wip features
rerun: <%= rerun_opts %> --format rerun --out rerun.txt --strict --tags ~@wip
report:  --format html --out=features.html
report_pdf: --format pdf --out=features.pdf
new: --tags @new
new_report: --format html --out=features_new.html --tags @new
new_report_pdf: --format pdf --out=features_new.pdf --tags @new 

默认值：功能
wip:--标记@wip:3--wip功能
rerun:--format rerun--out rerun.txt--strict--tags~@wip
报告：--格式html--out=features.html
报告pdf:--格式pdf--out=features.pdf
新建：--标记@new
新建报告：--format html--out=features_new.html--tags@new
新建报告\u pdf:--格式pdf--out=features\u new.pdf--tags@new

我必须升级黄瓜吗？或者降低对虾的等级

更新：我已经尝试在我的Gemfile和running捆绑包中使用最新的cucumber&prawn git repo（2011年5月24日）。我还是有同样的问题

更新：（18/07/2011） 遵循_-tk的建议并使用 $gem卸载对虾--版本=0.11.1

我有一个点燃的蜡烛

..rake aborted!
Command failed with status (1): [/home/map7/.rvm/rubies/ruby-1.9.2-p180/bin...]
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/file_utils.rb:53:in `block in create_shell_runner'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/file_utils.rb:45:in `call'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/file_utils.rb:45:in `sh'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/file_utils_ext.rb:36:in `sh'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-1.0.0/lib/cucumber/rake/task.rb:104:in `run'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/cucumber-1.0.0/lib/cucumber/rake/task.rb:193:in `block in define_task'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/task.rb:205:in `call'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/task.rb:205:in `block in execute'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/task.rb:200:in `each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/task.rb:200:in `execute'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain'
/home/map7/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/task.rb:144:in `invoke'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/application.rb:112:in `invoke_task'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/application.rb:90:in `block (2 levels) in top_level'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/application.rb:90:in `each'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/application.rb:90:in `block in top_level'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/application.rb:84:in `top_level'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/application.rb:62:in `block in run'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/lib/rake/application.rb:59:in `run'
/home/map7/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.9.2/bin/rake:32:in `<top (required)>'
/home/map7/.rvm/gems/ruby-1.9.2-p180/bin/rake:19:in `load'
/home/map7/.rvm/gems/ruby-1.9.2-p180/bin/rake:19:in `<main>'
Tasks: TOP => cucumber:new_report_pdf