Ruby on Rails / PostgreSQL - 启动服务器时出现库未加载错误

Question

Ruby on Rails / PostgreSQL - 启动服务器时出现库未加载错误

8

嘿，如果该问题已在其他主题中得到解答，请提前谅解。我已经在网站上搜索了，但没有找到答案。不过，最接近的相关问题是Ruby on Rails / PostgreSQL - Library not Loaded error when starting server- libq.5.dylib，但它从未得到解决，并且答案对我没有帮助。

我正在尝试在我的Mac OSX 10.6.8上运行PostgreSQL。我已经安装了Ruby 1.9.3p392和Rails 3.2.13。

由于我使用的是10.6.8版本，而PostGresApp需要10.7+，因此我尝试使用手动安装程序（v9.2.3）进行安装。下载链接：http://www.enterprisedb.com/products-services-training/pgdownload

我首先按照默认路径将其安装在/Library/PostgreSQL/9.2/。然后我安装了pg gem（PATH=$PATH:/Library/PostgreSQL/9.2/bin sudo gem install pg）。当我尝试用rails s来启动本地主机时，我遇到了下面的错误。

阅读一些资料后，我猜测可能是路径错误，因此我删除了pg gem，然后使用postgresql卸载程序。然后我在/users/stewartmccoy/Library/PostgreSQL/9.2/中重新安装了pg...然后重新安装了pg gem。但我仍然遇到同样的错误。

您认为我应该如何正确安装PostgreSQL并启动我的rails服务器呢？

stewart-mccoys-macbook:footy_subs stewartmccoy$ rails s
/Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/pg-0.14.1/lib/pg.rb:4:in `require': dlopen(/Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/pg-0.14.1/lib/pg_ext.bundle, 9): Library not loaded: libpq.5.dylib (LoadError)
  Referenced from: /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/pg-0.14.1/lib/pg_ext.bundle
  Reason: image not found - /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/pg-0.14.1/lib/pg_ext.bundle
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/pg-0.14.1/lib/pg.rb:4:in `<top (required)>'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler/runtime.rb:72:in `require'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler/runtime.rb:72:in `block (2 levels) in require'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler/runtime.rb:70:in `each'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler/runtime.rb:70:in `block in require'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler/runtime.rb:59:in `each'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler/runtime.rb:59:in `require'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler.rb:132:in `require'
    from /Users/stewartmccoy/Code/footy_subs/config/application.rb:13:in `<top (required)>'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/railties-3.2.13/lib/rails/commands.rb:53:in `require'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/railties-3.2.13/lib/rails/commands.rb:53:in `block in <top (required)>'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/railties-3.2.13/lib/rails/commands.rb:50:in `tap'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/railties-3.2.13/lib/rails/commands.rb:50:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'
stewart-mccoys-macbook:footy_subs stewartmccoy$ gem uninstall pgSuccessfully uninstalled pg-0.14.1
stewart-mccoys-macbook:footy_subs stewartmccoy$ PATH=$PATH:/users/stewartmccoy/Library/PostgreSQL/9.2/bin sudo gem install pg
Password:
Fetching: pg-0.14.1.gem (100%)
Building native extensions.  This could take a while...
Successfully installed pg-0.14.1
1 gem installed
Installing ri documentation for pg-0.14.1...
Installing RDoc documentation for pg-0.14.1...
stewart-mccoys-macbook:footy_subs stewartmccoy$ rails s
/Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/pg-0.14.1/lib/pg.rb:4:in `require': dlopen(/Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/pg-0.14.1/lib/pg_ext.bundle, 9): Library not loaded: libpq.5.dylib (LoadError)
  Referenced from: /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/pg-0.14.1/lib/pg_ext.bundle
  Reason: image not found - /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/pg-0.14.1/lib/pg_ext.bundle
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/pg-0.14.1/lib/pg.rb:4:in `<top (required)>'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler/runtime.rb:72:in `require'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler/runtime.rb:72:in `block (2 levels) in require'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler/runtime.rb:70:in `each'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler/runtime.rb:70:in `block in require'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler/runtime.rb:59:in `each'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler/runtime.rb:59:in `require'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.3.4/lib/bundler.rb:132:in `require'
    from /Users/stewartmccoy/Code/footy_subs/config/application.rb:13:in `<top (required)>'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/railties-3.2.13/lib/rails/commands.rb:53:in `require'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/railties-3.2.13/lib/rails/commands.rb:53:in `block in <top (required)>'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/railties-3.2.13/lib/rails/commands.rb:50:in `tap'
    from /Users/stewartmccoy/.rvm/gems/ruby-1.9.3-p392/gems/railties-3.2.13/lib/rails/commands.rb:50:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

- stewartm

1

感谢您提供合理的详细信息 - Pg版本，Pg软件包类型，主机操作系统等。 - Craig Ringer

可能是重复的问题：Ruby on Rails / PostgreSQL - Library not Loaded error when starting server- libq.5.dylib - bummi

3个回答

6

我想在这里添加一些意见，回答前面的问题。

有时候只需要重新安装pg gem即可。

gem uninstall pg && gem install pg

在我的情况下，我将postgresql服务器从 9.6 升级到了 14.x，而 dylib 路径也发生了改变。

/opt/local/lib/postgresql96/libpq.5.dylib -> /opt/local/lib/postgresql14/libpq.5.dylib

该 gem 使用 pg_config 来确定到 /opt/local/lib/postgresql[版本] 文件夹（命名为 PKGLIBDIR）的路径。为了构建 gem 的本地库，rake 在编译时通过从 pg_config 抓取动态库的路径来设置路径。一旦 pg gem 被编译，这些路径将会永久链接。因此，重新安装会重新编译和重新链接到新的库。

- Andrei Kovrov

在我的情况下，它甚至没有升级。pg-1.4.5只是被重新安装，然后它就可以工作了。很奇怪。 - michael_teter

2

一篇类似的stackoverflow答案建议从路径中删除Postgres.app，卸载pg宝石，并再次安装pg宝石。(我没有仔细检查是否适用于此问题，但它解决了我的一个问题，我想传播这个解决方案，因为我很难找到它。)

- David Winiecki

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- Craig Ringer · Accepted Answer

错误的关键部分是：

Library not loaded: libpq.5.dylib (LoadError)

这表明在运行时Ruby找不到libpq。为了解决这个问题，您可能需要设置DYLD_LIBRARY_PATH环境变量，指向您的PostgreSQL安装的lib目录，在全局范围内或在用于启动Rails的包装脚本中。有关更多信息，请参见此superuser问题。 Pg gem可以在编译和安装期间查找库，因为pg_config可执行文件在PATH上，并使用它来查找libpq。它似乎不会存储路径以供运行时使用，因此您必须自己设置运行时动态链接器。

一个简单的包装脚本（如果您不想修改全局环境）如下：

#!/bin/bash
export DYLD_LIBRARY_PATH=/path/to/pg/lib 
exec rails "$@"

"$@"基本上意味着“将所有参数直接传递到此脚本中”。它可以正确保留引号，并且基本上意味着rails命令无法告诉您未直接运行它。