Rails-MySQL Error - uninitialized constant MysqlCompat::MysqlRes

Question

Trying to get a Rails app running on Snow Leopard.

• Downloaded mysql-5.5.8-osx10.6-x86_64.dmg and ran installer
• Ruby 1.8.7 (Default OS X version)
• Rails 2.3.5

When I attempt to run "rake db:migrate" I get

• rake aborted!
• uninitialized constant MysqlCompat::MysqlRes

Yes I know this has been asked before. I have already reviewed the following links and followed the steps included in them and the result is the same each time.

• Rails, MySQL and Snow Leopard
• http://techliberty.blogspot.com/2009/12/dealing-with-rake-aborted-uninitialized.html
• http://www.schmidp.com/2009/06/14/rubyrails-and-mysql-on-snow-leopard-10a380/

Prior to the following commands I run "sudo gem uninstall mysql" followed by "sudo gem clean mysql" based on the above links:

• sudo gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config
• sudo env ARCHFLAGS="-arch x86_64" gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config

It is still failing. I am just flumoxed and would greatly appreciate any help.

Many thanks!

Answer 1

Not had the experience myself and I'm using Snow Leopard, RVM and rails 2.3.5 to 3.0.3, but found another view which deals with the uninstall and reinstall via :

export ARCHFLAGS="-arch i386 -arch x86_64" ;sudo gem install --no-rdoc --no-ri -v=2.7 mysql -- --with-mysql-dir=/usr/local/mysql --with-mysql-config=/usr/local/mysql/bin/mysql_config

For more details see the posting at: http://accidentaltechnologist.com/apple/fixing-uninitialized-constant-mysqlcompatmysqlres-error-on-snow-leopard/

Answer 2

For El Capitan you don't need to uninstall / install.

Just found your libmysqlclient.18.dylib file. Location will depent on how you installed mysql

locate libmysqlclient.18.dylib

Once you have the path create a symb link as:

ln -s /usr/local/mysql-5.5.20-osx10.6-x86_64/lib/libmysqlclient.18.dylib /usr/local/lib/libmysqlclient.18.dylib

You have two change first param according to your dynamic library location (use the first command).

On El Capitan the link should be to /usr/local/lib. On previous versions link was to /usr/lib/