Error requiring pg under rvm with postgres.app

问题:

I'm using Postgres.app on OS X (10.8.3). I have modified my PATH so that the bin folder for the app is before all others.

Rammy:~ phrogz$ which pg_config
/Applications/Postgres.app/Contents/MacOS/bin/pg_config

I have rvm installed and can install the pg gem without error, but when I go to require it I get an error:

Rammy:~ phrogz$ gem -v
1.8.25

Rammy:~ phrogz$ gem install pg
Fetching: pg-0.15.1.gem (100%)
Building native extensions.  This could take a while...
Successfully installed pg-0.15.1
1 gem installed

Rammy:~ phrogz$ ruby -v -e "require 'pg'"
ruby 1.9.3p392 (2013-02-22 revision 39386) [x86_64-darwin12.3.0]
/Users/phrogz/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require': dlopen(/Users/phrogz/.rvm/gems/ruby-1.9.3-p392/gems/pg-0.15.1/lib/pg_ext.bundle, 9): Library not loaded: @executable_path/../lib/libssl.1.0.0.dylib (LoadError)
  Referenced from: /Applications/Postgres.app/Contents/MacOS/lib/libpq.dylib
  Reason: image not found - /Users/phrogz/.rvm/gems/ruby-1.9.3-p392/gems/pg-0.15.1/lib/pg_ext.bundle
    from /Users/phrogz/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
    from /Users/phrogz/.rvm/gems/ruby-1.9.3-p392/gems/pg-0.15.1/lib/pg.rb:4:in `<top (required)>'
    from /Users/phrogz/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:60:in `require'
    from /Users/phrogz/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:60:in `rescue in require'
    from /Users/phrogz/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:35:in `require'
    from -e:1:in `<main>'

What do I need to do to get the pg gem properly installed?

回答1:

This worked for me:

sudo env ARCHFLAGS="-arch x86_64" gem install pg -- --with-pg-config=/Applications/Postgres93.app/Contents/MacOS/bin/pg_config

Just double check that the /Applications/Postgres93.app.. path exists for you.

回答2:

Edit: Even though this answer currently has more votes than the accepted answer, the accepted answer is far simpler and cleaner.

---

Remove the Postgres.app binaries from the path when installing the pg gem, and instead use the postgres install built into OS X to configure the gem. The pg library will still correctly connect to the Postgres.app server later on.

Rammy:~ phrogz$ gem uninstall pg
Successfully uninstalled pg-0.15.1

# Modify PATH to remove /Applications/Postgres.app/Contents/MacOS/bin

Rammy:~ phrogz$ gem install pg
Fetching: pg-0.15.1.gem (100%)
Building native extensions.  This could take a while...
Successfully installed pg-0.15.1
1 gem installed

Rammy:~ phrogz$ ruby -v -e "require 'pg'"
ruby 1.9.3p392 (2013-02-22 revision 39386) [x86_64-darwin12.3.0]

回答3:

I found a solution that works for me and requires minimal hacking/configuring. You only need to do this once and it will work for every bundle install. Add the following to your .bash_profile, .bash_rc, or equivalent:

export DYLD_FALLBACK_LIBRARY_PATH=/Applications/Postgres.app/Contents/MacOS/lib:$DYLD_LIBRARY_PATH

(Assuming you installed Postgres.app in the default location). Then restart your terminal session and try again.

Exporting to DYLD_LIBRARY_PATH directly can cause serious problems with other apps that depend on it, but using the fallback path avoids these problems.

See also:

• https://github.com/PostgresApp/PostgresApp/issues/109#issuecomment-18387546
• Postgres.app upgrade, now Rails app won't start

EDIT: It seems that setting DYLD_FALLBACK_LIBRARY_PATH causes an error when you try to run psql. To fix this, you can add the following two lines to your .bash_profile:

alias psql="(. ~/.bash_profile; unset DYLD_FALLBACK_LIBRARY_PATH; psql)";

This is assuming that you're using bash and that your .bash_profile is located in your home directory. If that's not the case (or if you're using a .bashrc or other environment setup instead of .bash_profile) change the ~/.bash_profile part of the command to the path to your environment setup script.

The aliased commands basically start a subshell which does not effect your current bash environment. So when it unsets the DYLD_FALLBACK_LIBRARY_PATH variable, it's only temporary. After you exit psql the environment variable will be set again so that rails functions properly.

回答4:

The problem is in the linking of the gem to the Postgres.app. If you link it to the postgres version that ships with osx

Here's a small script:

• if using rvm with project gemsets: change into your project

• run the following commands:

  gem uninstall pg
  
  PATH=${PATH/'Postgres.app'/'WRONGFOLDER.app'}
  gem install pg
  PATH=${PATH/'WRONGFOLDER.app'/'Postgres.app'}
  

• Now everthing should be fine