我尝试过并尝试过。然而它仍然存在以下错误：
Error message:
Could not find i18n-0.7.0 in any of the sources (Bundler::GemNotFound)
我尝试升级bundler，后来升级了i18n（尽管两者都已经准备好并升级了：
root@devgit:/usr/local/share/redmine# gem install bundler
Fetching: bundler-1.9.2.gem (100%)
Successfully installed bundler-1.9.2
1 gem installed
Installing ri documentation for bundler-1.9.2...
Installing RDoc documentation for bundler-1.9.2...
root@devgit:/usr/local/share/redmine# gem instal i18n
Successfully installed i18n-0.7.0
1 gem installed
Installing ri documentation for i18n-0.7.0...
Installing RDoc documentation for i18n-0.7.0...
root@devgit:/usr/local/share/redmine#
那么，还有什么可以尝试的？
编辑：
root@devgit:/usr/local/share/redmine# bundle install
Don't run Bundler as root. Bundler can ask for sudo if it is needed, and
installing your bundle as root will break this application for all non-root
users on this machine.
Your Gemfile lists the gem activerecord-jdbcmysql-adapter (>= 0) more than once.
You should probably keep only one of them.
While it's not a problem now, it could cause errors if you change the version of just one of them later.
Using rake 10.4.2
Using i18n 0.7.0
Using json 1.8.2
Using minitest 5.5.1
Using thread_safe 0.3.5
Using tzinfo 1.2.2
Using activesupport 4.2.0
Using builder 3.2.2
Using erubis 2.7.0
Using mini_portile 0.6.2
Using nokogiri 1.6.6.2
Using rails-deprecated_sanitizer 1.0.3
Using rails-dom-testing 1.0.6
Using loofah 2.0.1
Using rails-html-sanitizer 1.0.2
Using actionview 4.2.0
Using rack 1.6.0
Using rack-test 0.6.3
Using actionpack 4.2.0
Using globalid 0.3.3
Using activejob 4.2.0
Using mime-types 2.4.3
Using mail 2.6.3
Using actionmailer 4.2.0
Using actionpack-action_caching 1.1.1
Using actionpack-xml_parser 1.0.1
Using activemodel 4.2.0
Using arel 6.0.0
Using activerecord 4.2.0
Using coderay 1.1.0
Using hike 1.2.3
Using thor 0.19.1
Using railties 4.2.0
Using jquery-rails 3.1.2
Using multi_json 1.11.0
Using mysql2 0.3.18
Using net-ldap 0.3.1
Using pg 0.17.1
Using protected_attributes 1.0.9
Using ruby-openid 2.3.0
Using rack-openid 1.4.2
Using bundler 1.9.2
Using tilt 1.4.1
Using sprockets 2.12.3
Using sprockets-rails 2.2.4
Using rails 4.2.0
Using rbpdf 1.18.5
Using redcarpet 3.1.2
Using request_store 1.0.5
Using rmagick 2.14.0
Using sqlite3 1.3.10
Bundle complete! 34 Gemfile dependencies, 51 gems now installed.
Gems in the groups development, test, postgresql and sqlite were not installed.
Use `bundle show [gemname]` to see where a bundled gem is installed.
root@devgit:/usr/local/share/redmine# bundle show i18n
/usr/local/rvm/gems/ruby-2.2.1/gems/i18n-0.7.0
root@devgit:/usr/local/share/redmine#