uninitialized constant MysqlCompat::MysqlRes (using mms2r gem)

Question

moved a rails app of mine onto a new server and had to install a few gem dependencies. However, after installing the mysql gem I get the error, uninitialized constant Mysql

Answer 1

This is what worked for me. I read a ton of posts and found that using the system ruby install was causing an incompatibility issue:

1. don't use default ruby install! install ruby with macports
2. don't use default rubygems install! install rb-rubygems with macports
3. use mysql 5.1 (not 5.5) - installed from mysql.com mac .dmg
4.

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

Answer 2

gem install -v=2.7.1 will fix it as well.

Answer 3

sudo gem install mysql -v 2.7 -- --with-mysql-config=/usr/local/mysql/bin/mysql_config also did the trick for me when migrating over to my new Snow Leopard laptop. I did not use MacPorts to install mysql, but rather the binary, and had no luck with the arch flag solutions or symlinks.

Answer 4

I've tried all of the above and none of them work for me either. When trying to install mysql version 2.7, I get the error:

sudo gem install -v=2.7.1 mysql -- --with-mysql-dir=/usr/local/mysql-5.1.39-osx10.5-powerpc/bin/mysql_config
ERROR:  could not find gem mysql locally or in a repository
F107PHD:stepgreen.org tdillahu$ sudo gem install -v=2.7 mysql -- --with-mysql-dir=/usr/local/mysql-5.1.39-osx10.5-powerpc/bin/mysql_config
Building native extensions.  This could take a while...
ERROR:  Error installing mysql:
    ERROR: Failed to build gem native extension.

/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb --with-mysql-dir=/usr/local/mysql-5.1.39-osx10.5-powerpc/bin/mysql_config
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lm... no
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lz... no
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lsocket... no
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lnsl... no
checking for mysql_query() in -lmysqlclient... no
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Provided configuration options:
    --with-opt-dir
    --without-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
    --without-make-prog
    --srcdir=.
    --curdir
    --ruby=/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby
    --with-mysql-config
    --without-mysql-config
    --with-mysql-dir
    --with-mysql-include
    --without-mysql-include=${mysql-dir}/include
    --with-mysql-lib
    --without-mysql-lib=${mysql-dir}/lib
    --with-mysqlclientlib
    --without-mysqlclientlib
    --with-mlib
    --without-mlib
    --with-mysqlclientlib
    --without-mysqlclientlib
    --with-zlib
    --without-zlib
    --with-mysqlclientlib
    --without-mysqlclientlib
    --with-socketlib
    --without-socketlib
    --with-mysqlclientlib
    --without-mysqlclientlib
    --with-nsllib
    --without-nsllib
    --with-mysqlclientlib
    --without-mysqlclientlib


Gem files will remain installed in /Library/Ruby/Gems/1.8/gems/mysql-2.7 for inspection.
Results logged to /Library/Ruby/Gems/1.8/gems/mysql-2.7/gem_make.out

My original error: ake aborted! uninitialized constant MysqlCompat::MysqlRes /vendor/rails/activesupport/lib/active_support/dependencies.rb:440:in load_missing_constant' /vendor/rails/activesupport/lib/active_support/dependencies.rb:80:inconst_missing'

Answer 5

My problem was due to my "mysql" being a 32-bit installation while ruby was 64 and 32-bit. Check with these commands

 file `which mysql` 
 file `which ruby`

Both should match Mach-O 64-bit executable x86_64 or Mach-O 64-bit executable i386. I installed a 64-bit mysql, then

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

and voila!

Answer 6

sudo gem install mysql -v 2.7 should do the trick...