Ruby on Rails / PostgreSQL - 啟動服務器時庫未加載錯誤

Question

嘿嘿。 如果這個問題已經在另一個線程中得到回答，我提前道歉。 我已經搜索了該網站，但沒有找到答案。 但是，最接近的相關問題是Ruby on Rails / PostgreSQL - Library not Loaded error when started server- libq.5.dylib ，但從未解決，答案對我沒有幫助。

我試圖讓 PostgreSQL 在我的 Mac OSX 10.6.8 上運行。 我已經安裝了 Ruby 1.9.3p392 和 Rails 3.2.13。

由於我有 10.6.8，而 PostGresApp 需要 10.7+，我嘗試使用此處提供的手動安裝程序 (v9.2.3) 安裝 PG： http://www.enterprisedb.com/products-services-training/pgdownload

我首先將它安裝到默認路徑：/Library/PostgreSQL/9.2/。 然后我安裝了 pg gem（ PATH=$PATH:/Library/PostgreSQL/9.2/bin sudo gem install pg ）。 當我嘗試使用rails s啟動我的 localhost 時，出現以下錯誤。

經過一番閱讀，我猜測可能是路徑錯誤，所以我刪除了 pg gem，然后使用了 postgresql 卸載程序。 然后我在 /users/stewartmccoy/Library/PostgreSQL/9.2/... 中重新安裝了 pg，然后重新安裝了 pg gem。 但我仍然得到同樣的錯誤。

關於如何正確安裝 PostgreSQL 並讓我的 rails 服務器運行的任何想法？

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>'

Answer 1

錯誤的關鍵部分是：

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

這表明ruby在運行時找不到libpq 。 為了解決這個問題，您應該將DYLD_LIBRARY_PATH環境變量設置為指向PostgreSQL安裝的lib目錄，無論是全局還是用於啟動Rails的包裝腳本。 有關更多信息，請參閱此超級用戶問題 。

Pg gem可以在編譯和安裝期間找到庫，因為pg_config可執行文件位於PATH ，並使用它來查找libpq 。 它似乎不存儲在運行時使用的路徑，因此您必須自己設置運行時動態鏈接器。

一個簡單的包裝腳本（如果你不想修改你的全局環境）是這樣的：

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

“$ @”基本上意味着“將所有參數傳遞給此腳本，就好像它們是直接傳遞給這里一樣”。 它保留了正確的引用，實質上意味着rails命令無法告訴你沒有直接運行它。

Answer 2

類似的stackoverflow答案建議從你的PATH中刪除Postgres.app，卸載pg gem，然后再次安裝pg gem。

（我沒有花時間仔細檢查這是否適用於這個問題，但它解決了我遇到的問題，因為我無法找到它，所以我想傳播解決方案。）

Answer 3

我想把我的兩分錢放在上面的答案上。

有時只需重新安裝pg gem 就足夠了。

gem uninstall pg && gem install pg

就我而言，我將 postgresql 服務器從9.6升級到14.x ，並且更改了 dylib 路徑。

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

gem 使用pg_config來確定/opt/local/lib/postgresql[version]文件夾（名為PKGLIBDIR ）的路徑。 要為 gem rake 構建本機庫，通過在 compile 中從pg_config中獲取動態庫來設置動態庫的路徑。 編譯pg gem 后，路徑將永遠鏈接。 因此，重新安裝會重新編譯並將路徑重新鏈接到新庫。