I'm getting the following error when I start rails server:
$ rails server
/Users/ssmith/.rvm/gems/ruby-1.9.2-p0/gems/mysql2-0.2.6/lib/mysql2.rb:7:in `require': dlopen(/Users/ssmith/.rvm/gems/ruby-1.9.2-p0/gems/mysql2-0.2.6/lib/mysql2/mysql2.bundle, 9): Library not loaded: libmysqlclient.16.dylib (LoadError)
Referenced from: /Users/ssmith/.rvm/gems/ruby-1.9.2-p0/gems/mysql2- 0.2.6/lib/mysql2/mysql2.bundle
Reason: image not found - /Users/ssmith/.rvm/gems/ruby-1.9.2-p0/gems/mysql2-
0.2.6/lib/mysql2/mysql2.bundle
I've installed mysql2 with the following command after the rvm use ruby-1.9.2-p0 command:
$ gem install mysql2 -- --with-mysql-dir=/usr/local/mysql --with-mysql-config=/usr/local/mysql/bin/mysql_config
Building native extensions. This could take a while...
Successfully installed mysql2-0.2.6
1 gem installed
Installing ri documentation for mysql2-0.2.6...
Enclosing class/module 'mMysql2' for class Client not known
Installing RDoc documentation for mysql2-0.2.6...
Enclosing class/module 'mMysql2' for class Client not known
I have mysql2 in my Gemfile as well as in the database.yml file and bundle install completes fine
$ bundle show mysql2
/Users/ssmith/.rvm/gems/ruby-1.9.2-p0/gems/mysql2-0.2.6
I understand the rails server error is due to it not knowing the mysql_config location on OSX, however on gem install I specified the correct location. Yet RVM's gem is not respecting that mysql_config location it seems.
Anyone have a solution to this?
The problem comes from the mysql2 gem missing the dynamic library from MySQL.
A cleaner solution than install_name_tool ... would need to update your DYLD_LIBRARY_PATH to add MySQL libs to it. To do so, update your ~/.bash_profile to add the MySQL library folder :
export DYLD_LIBRARY_PATH="/usr/local/mysql/lib:$DYLD_LIBRARY_PATH"
Note: You might want to update the MySQL location based on your install
This should keep things clean but also ensure that any gem or code requiring MySQL dynamic libraries will find them.
Reference : http://lightyearsoftware.com/2011/02/mysql-5-5-on-mac-os-x/
Reference Update July 2012: A change in OS X 10.8 makes the easy method above less elegant. If you set that variable, every time you run a setuid or setgid program, you get this warning on stderr:
dyld: DYLD_ environment variables being ignored because main executable (...) is setuid or setgid
Ruby developers using Phusion Passenger Standalone will see this message displayed in their console every five seconds. It gets really irritating, very fast.
I have filed a bug with Apple. It’s also at OpenRadar.
In the meantime, there is also a third way to fix the client library path problem that doesn’t require setting DYLD_LIBRARY_PATH (working around this 10.8 issue) or hacking .bundle files with install_name_tool:
$ brew install mysql
I found the answer here: Mysql 5.5, Snow leopard and rails
sudo install_name_tool -change libmysqlclient.16.dylib /usr/local/mysql/lib/libmysqlclient.16.dylib ~/.rvm/gems/ruby-1.9.2-p0/gems/mysql2-0.2.6/lib/mysql2/mysql2.bundle
On OS X 10.8 (Mountain Lion), the listed answers all have issues, as noted in the answers and comments.
- Setting
DYLD_LIBRARY_PATHto include /usr/local/mysql/lib gives warnings from OS X and from brew - Using
install_name_toolto hack where the gem binary looks would need to be redone each time the gem is installed or upgraded. - Switch to
brew's mysql may not work; and in any case I don't want to reconfigure an already-working installation
A simpler and robust solution IMHO is to put a link to the library in the default dynamic library search path, which conveniently includes /usr/local/lib. That is:
ln -s /usr/local/mysql/lib/libmysqlclient.18.dylib /usr/local/lib
Bill,
Frederic's answer will solve this problem, however you may have to change some of the items in the command depending on versions and how things are named on your system.
For example, on the most recent version of mysql libmysqlclient.16.dylib is actually libmysqlclient.18.dylib. Try doing a:
locate libmysqlclient.18.dylib
If that does not return the path you can go to:
/usr/local/{your-mysql}/lib
to find the file. Then just a PWD to find the correct directory for the command.
You will also need to determine what the actual package names of the rubies you have installed are. You can find this by using
rvm info
For example, my installation of 1.9.2 is ruby-1.9.2.p180, not ruby-1.9.2p0. This will need to be changed in Frederics command as well.
So, for me Frederic's command became for fixing the rvm rubies for 1.8.7 and 1.9.2, respectively:
sudo install_name_tool -change libmysqlclient.18.dylib /usr/local/mysql-5.5.10-osx10.6-x86_64/lib/libmysqlclient.18.dylib ~/.rvm/gems/ruby-1.8.7-p334/gems/mysql2-0.2.6/lib/mysql2/mysql2.bundle
sudo install_name_tool -change libmysqlclient.18.dylib /usr/local/mysql-5.5.10-osx10.6-x86_64/lib/libmysqlclient.18.dylib ~/.rvm/gems/ruby-1.9.2-p180/gems/mysql2-0.2.6/lib/mysql2/mysql2.bundle
below via: http://lightyearsoftware.com/2011/02/mysql-5-5-on-mac-os-x/
Update July 2012:
A change in OS X 10.8 makes the easy method above less elegant. If you set that variable, every time you run a setuid or setgid program, you get this warning on stderr:
dyld: DYLD_ environment variables being ignored because main executable (...) is setuid or setgid
Ruby developers using Phusion Passenger Standalone will see this message displayed in their console every five seconds. It gets really irritating, very fast.
I have filed a bug with Apple. It’s also at OpenRadar.
In the meantime, there is also a third way to fix the client library path problem that doesn’t require setting DYLD_LIBRARY_PATH (working around this 10.8 issue) or hacking .bundle files with install_name_tool:
$ brew install mysql
Mine was in a different location, I had to use:
sudo install_name_tool -change libmysqlclient.18.dylib /usr/local/mysql/lib/libmysqlclient.18.dylib /Library/Ruby/Gems/1.8/gems/mysql2-0.3.11/lib/mysql2/mysql2.bundle.
I was stuck on this for a while and came to a different solution.
Notice how the missing library is version 16:
Library not loaded: libmysqlclient.16.dylib (LoadError)
Turns out I had version 20 of that library - libmysqlclient.20.dylib
I correctly had gem 'mysql2' in my Gemfile, but what I needed to do was uninstall the gem, gem uninstall mysql (I had multiple versions of the gem installed) and then doing a new bundle install to get just the version I needed of this library.
After that it looked for - and found - the correct version of that lib.
Here is what I do (similar to others)
sudo install_name_tool -change libmysqlclient.18.dylib /usr/local/mysql/lib/libmysqlclient.18.dylib ~/.rvm/gems/ruby-1.9.2-p290/gems/mysql2-0.3.10/lib/mysql2/mysql2.bundle
Upgraded mysql to latest version and reinstall mysql2 gem works to me
brew upgrade mysql
gem uninstall mysql2
gem install mysql2
BTW: My MySQL version is 5.7.18, mysql2 gem version is 0.4.5
来源：https://stackoverflow.com/questions/4512362/rails-server-fails-to-start-with-mysql2-using-rvm-ruby-1-9-2-p0-on-osx-10-6-5