我有一个运行Ruby 1.9.2、Rails 3和postgreSQL 8.3的应用程序。它最初是安装并使用postgreSQL 9.1的，但我卸载了9.1并安装并更改为8.3，以确保在Heroku共享数据库设置上的兼容性。它运行正常，但现在不是
现在，当我在这个应用程序上工作时，当我运行数据库升级时，我会得到这个错误：
dlopen(/Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290/gems/pg-0.12.2/lib/pg_ext.bundle, 9): Library not loaded: libpq.5.dylib
Referenced from: /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290/gems/pg-0.12.2/lib/pg_ext.bundle
Reason: no suitable image found. Did find:
/usr/lib/libpq.5.dylib: no matching architecture in universal wrapper - /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290/gems/pg-0.12.2/lib/pg_ext.bundle
当我尝试运行服务器时，我会收到以下错误消息：
/Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290/gems/pg-0.12.2/lib/pg.rb:4:in `require': dlopen(/Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290/gems/pg-0.12.2/lib/pg_ext.bundle, 9): Library not loaded: libpq.5.dylib (LoadError)
Referenced from: /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290/gems/pg-0.12.2/lib/pg_ext.bundle
Reason: no suitable image found. Did find:
/usr/lib/libpq.5.dylib: no matching architecture in universal wrapper - /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290/gems/pg-0.12.2/lib/pg_ext.bundle
from /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290/gems/pg-0.12.2/lib/pg.rb:4:in `<top (required)>'
from /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290@global/gems/bundler-1.0.21/lib/bundler/runtime.rb:68:in `require'
from /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290@global/gems/bundler-1.0.21/lib/bundler/runtime.rb:68:in `block (2 levels) in require'
from /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290@global/gems/bundler-1.0.21/lib/bundler/runtime.rb:66:in `each'
from /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290@global/gems/bundler-1.0.21/lib/bundler/runtime.rb:66:in `block in require'
from /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290@global/gems/bundler-1.0.21/lib/bundler/runtime.rb:55:in `each'
from /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290@global/gems/bundler-1.0.21/lib/bundler/runtime.rb:55:in `require'
from /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290@global/gems/bundler-1.0.21/lib/bundler.rb:122:in `require'
from /Users/michaeljmccoy/www/mikemccoy/config/application.rb:7:in `<top (required)>'
from /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.0.rc2/lib/rails/commands.rb:53:in `require'
from /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.0.rc2/lib/rails/commands.rb:53:in `block in <top (required)>'
from /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.0.rc2/lib/rails/commands.rb:50:in `tap'
from /Users/michaeljmccoy/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.0.rc2/lib/rails/commands.rb:50:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'
我知道它们是非常相似的错误，可能与丢失的路径有关。但是，当我将路径添加到.profile文件并重新启动终端窗口时，我会收到同样的错误。
您可能需要删除并重新安装pg-gem，因此它是根据正确版本的Postgres编译的。
对于任何看到此错误并运行PostgresApp的人来说，这是一个在9.2.4.3:版本中修复的已知问题
讨论：https://github.com/PostgresApp/PostgresApp/issues/109
安装程序：https://github.com/PostgresApp/PostgresApp/releases/tag/9.2.4.3
当然，您可以直接获取最新版本(http://postgresapp.com/)。这两个版本都让我重新开始使用Rails 3.2.14和Ruby 2.0.0。但是，请注意，当我安装9.2.4.3时，我的数据库仍在psql中列出，但当我安装9.3.0（目前的当前版本）时，我不再列出我的数据库。