ERROR: While executing gem ... (Gem::DependencyError) Unable to resolve dependencies: lazyman requires active_support (~> 3.0.0)

[wuhlcom]

I don't understand why the DependencyError appears
Could you please help me?
RubyGems Environment:

• RUBYGEMS VERSION: 1.8.29
• RUBY VERSION: 1.9.3 (2014-11-13 patchlevel 551) [i386-mingw32]
• INSTALLATION DIRECTORY: C:/Ruby193/lib/ruby/gems/1.9.1
• RUBY EXECUTABLE: C:/Ruby193/bin/ruby.exe
• EXECUTABLE DIRECTORY: C:/Ruby193/bin
• RUBYGEMS PLATFORMS:
  • ruby
  • x86-mingw32
• GEM PATHS:
  • C:/Ruby193/lib/ruby/gems/1.9.1
  • C:/Users/zhilu1234/.gem/ruby/1.9.1
• GEM CONFIGURATION:
  • :update_sources => true
  • :verbose => true
  • :benchmark => false
  • :backtrace => false
  • :bulk_threshold => 1000
  • :sources => ["https://ruby.taobao.org/"]
• REMOTE SOURCES:
  • https://ruby.taobao.org/

Microsoft Windows [版本 6.1.7601](WIN7 64 bit)
版权所有 (c) 2009 Microsoft Corporation。保留所有权利。

C:\Users\zhilu1234>gem install lazyman
ERROR: While executing gem ... (Gem::DependencyError)
Unable to resolve dependencies: lazyman requires active_support (~> 3.0.0)

C:\Users\zhilu1234>gem list active

*** LOCAL GEMS ***

activejob (4.2.1)
activemodel (4.2.1)
activerecord (4.2.1)
activesupport (4.2.1, 3.0.0)

C:\Users\zhilu1234>