ruby – irb中的所有命令给出“NoMethodError：未定义的方法`write’for nil：NilClass”

我试图从IRB获取当前的 ruby版本,但它给了我这个错误：

>> RUBY_VERSION
NoMethodError: undefined method `write' for nil:NilClass
    from /usr/local/lib/ruby/1.9.1/irb.rb:311:in `printf'
    from /usr/local/lib/ruby/1.9.1/irb.rb:311:in `output_value'
    from /usr/local/lib/ruby/1.9.1/irb.rb:160:in `block (2 levels) in eval_input'
    from /usr/local/lib/ruby/1.9.1/irb.rb:273:in `signal_status'
    from /usr/local/lib/ruby/1.9.1/irb.rb:156:in `block in eval_input'
    from /usr/local/lib/ruby/1.9.1/irb/ruby-lex.rb:243:in `block (2 levels) in each_top_level_statement'
    from /usr/local/lib/ruby/1.9.1/irb/ruby-lex.rb:229:in `loop'
    from /usr/local/lib/ruby/1.9.1/irb/ruby-lex.rb:229:in `block in each_top_level_statement'
    from /usr/local/lib/ruby/1.9.1/irb/ruby-lex.rb:228:in `catch'
    from /usr/local/lib/ruby/1.9.1/irb/ruby-lex.rb:228:in `each_top_level_statement'
    from /usr/local/lib/ruby/1.9.1/irb.rb:155:in `eval_input'
    from /usr/local/lib/ruby/1.9.1/irb/ext/multi-irb.rb:166:in `block (2 levels) in irb'
    from /usr/local/lib/ruby/1.9.1/irb/ext/multi-irb.rb:165:in `catch'
    from /usr/local/lib/ruby/1.9.1/irb/ext/multi-irb.rb:165:in `block in irb'
Maybe IRB bug!

ruby -v显示ruby 1.9.3p0(2011-10-30修订版33570)[x86_64-darwin11.2.0]

我正在使用Mac OS X Lion

更新：
实际上,它根本没有运行任何东西.

>> a = 'Hello,World!'
NoMethodError: undefined method `write' for nil:NilClass
    from /usr/local/lib/ruby/1.9.1/irb.rb:311:in `printf'
    from /usr/local/lib/ruby/1.9.1/irb.rb:311:in `output_value'
    from /usr/local/lib/ruby/1.9.1/irb.rb:160:in `block (2 levels) in eval_input'
    from /usr/local/lib/ruby/1.9.1/irb.rb:273:in `signal_status'
    from /usr/local/lib/ruby/1.9.1/irb.rb:156:in `block in eval_input'
    from /usr/local/lib/ruby/1.9.1/irb/ruby-lex.rb:243:in `block (2 levels) in each_top_level_statement'
    from /usr/local/lib/ruby/1.9.1/irb/ruby-lex.rb:229:in `loop'
    from /usr/local/lib/ruby/1.9.1/irb/ruby-lex.rb:229:in `block in each_top_level_statement'
    from /usr/local/lib/ruby/1.9.1/irb/ruby-lex.rb:228:in `catch'
    from /usr/local/lib/ruby/1.9.1/irb/ruby-lex.rb:228:in `each_top_level_statement'
    from /usr/local/lib/ruby/1.9.1/irb.rb:155:in `eval_input'
    from /usr/local/lib/ruby/1.9.1/irb/ext/multi-irb.rb:166:in `block (2 levels) in irb'
    from /usr/local/lib/ruby/1.9.1/irb/ext/multi-irb.rb:165:in `catch'
    from /usr/local/lib/ruby/1.9.1/irb/ext/multi-irb.rb:165:in `block in irb'
Maybe IRB bug!

更新#2 :(对于锡人)
使用/usr/bin/irb,我明白了

>> 5+5
NoMethodError: undefined method `write' for nil:NilClass
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:310:in `printf'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:310:in `output_value'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:159:in `eval_input'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:271:in `signal_status'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:155:in `eval_input'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb/ruby-lex.rb:244:in `each_top_level_statement'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb/ruby-lex.rb:230:in `loop'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb/ruby-lex.rb:230:in `each_top_level_statement'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb/ruby-lex.rb:229:in `catch'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb/ruby-lex.rb:229:in `each_top_level_statement'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:154:in `eval_input'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:71:in `start'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:70:in `catch'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:70:in `start'
    from /usr/bin/irb:13
Maybe IRB bug!!

解决方法

尝试使用/usr/bin/irb来获取Apple的Ruby安装.

使用Leopard的说明在Lion上安装Ruby并不是一个好主意.您必须记住语言和操作系统细节会发生变化.

“Building Ruby 1.9.3 on Lion with Xcode 4.2 using ./configure –with-gcc=clang”的信息应该有所帮助. “Error installing 1.9.3 with RVM on Lion”也提供了有关XCode的有用信息.