mysql - 安装 mysql2 适配器时出错 : Please install the mysql2 adapter: `gem install activerecord-mysql2-adapter` (cannot load such file -- mysql2/mysql2)

Question

我在运行 Redmine2.3-stable 时遇到这个错误，随后无法成功安装 mysql2 适配器。

这是错误:

    Please install the mysql2 adapter: `gem install activerecord-mysql2-adapter` (cannot load such file -- mysql2/mysql2)

我在运行网站、通过 passenger 和运行 rake db:migrate 时得到这个

适配器已安装:

gem list

* 本地 gem *

actionmailer (3.2.13)
actionpack (3.2.13)
activemodel (3.2.13)
activerecord (3.2.13)
activerecord-mysql2-adapter (0.0.3)
activeresource (3.2.13)
activesupport (3.2.13)
afm (0.2.0)
arel (3.0.2)
Ascii85 (1.0.2)
bigdecimal (1.1.0)
builder (3.0.4, 3.0.0)
bundler (1.3.4)
coderay (1.0.9)
daemon_controller (1.1.2)
daemons (1.1.9)
erubis (2.7.0)
eventmachine (1.0.3)
fastthread (1.0.7)
hashery (2.1.0)
hike (1.2.1)
holidays (1.0.5)
i18n (0.6.1)
icalendar (1.2.3)
io-console (0.3)
journey (1.0.4)
jquery-rails (2.0.3)
json (1.7.7, 1.5.4)
mail (2.5.3)
mime-types (1.21)
minitest (4.7.0, 2.5.1)
multi_json (1.7.2)
mysql2 (0.3.11)
net-ldap (0.3.1)
nokogiri (1.5.9)
open-uri-cached (0.0.5)
passenger (3.0.19)
pdf-reader (1.3.2)
polyglot (0.3.3)
prawn (0.12.0)
rack (1.4.5)
rack-cache (1.2)
rack-openid (1.3.1)
rack-ssl (1.3.3)
rack-test (0.6.2)
rails (3.2.13)
railties (3.2.13)
rake (10.0.4, 0.9.2.2)
rdoc (3.12.2, 3.9.4)
ruby-openid (2.1.8)
ruby-rc4 (0.1.5)
rubygems-update (2.0.3)
sprockets (2.2.2)
thin (1.5.1)
thor (0.17.0)
tilt (1.3.6)
treetop (1.4.12)
ttfunk (1.0.3)
tzinfo (0.3.37)

ruby -v

ruby 1.9.3p194 (2012-04-20 revision 35410) [x86_64-linux]

gem 环境

- RUBYGEMS VERSION: 2.0.3
- RUBY VERSION: 1.9.3 (2012-04-20 patchlevel 194) [x86_64-linux]
- INSTALLATION DIRECTORY: /usr/local/lib/ruby/gems/1.9.1
- RUBY EXECUTABLE: /usr/local/bin/ruby
- EXECUTABLE DIRECTORY: /usr/local/bin
- RUBYGEMS PLATFORMS:
  - ruby
  - x86_64-linux
- GEM PATHS:
   - /usr/local/lib/ruby/gems/1.9.1
   - /root/.gem/ruby/1.9.1
- GEM CONFIGURATION:
   - :update_sources => true
   - :verbose => true
   - :backtrace => false
   - :bulk_threshold => 1000
- REMOTE SOURCES:
   - https://rubygems.org/

根据此处的建议，我尝试通过编辑 Gemfile 将 redmine 强制为 rails3.2.2:

Rails 3.2.2 mysql2 adapter Error

注释

我必须使用下面的命令强制安装 gem mysql2 bundle 才能工作(我收到有关 errormsg.h 的错误)。

sudo gem install activerecord-mysql2-adapter -- --srcdir=/usr/include/mysql/

有什么想法吗？

Answer 1

在您的 Gemfile 中包含 mysql2 gem，并将 database.yml 中的适配器更改为 mysql2，然后进行捆绑安装。它会解决你的问题..