我用的rails 1.2.6, gem 1.1.1 安装了gettext 1.91，在rails 的 config/environment.rb文件顶部加了require 'gettext/rails'后报错。
在irb里运行
require 'ruybgems'
require 'gettext/rails'

NameError: uninitialized constant Rails
    from /usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/dependencies.rb:266:in `load_missing_constant'
    from /usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/dependencies.rb:452:in `const_missing'
    from /usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/dependencies.rb:464:in `const_missing'
    from /usr/local/lib/ruby/gems/1.8/gems/gettext-1.9.0/lib/gettext/rails.rb:24
    from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require'
    from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require'
    from (irb):3
    from /usr/local/lib/ruby/site_ruby/1.8/rubygems/requirement.rb:119
>> qui
NameError: undefined local variable or method `qui' for main:Object
    from (irb):4
    from /usr/local/lib/ruby/site_ruby/1.8/rubygems/requirement.rb:119
>> quit
请问大家如何解决这个问题？

问题解决了。原来是安装的gettext版本的问题。现在gettext1.91的版本是支持2.0.x的。不支持1.2.x，换了gettext 1.10后，正确了。