[FIXED] "gem install mysql2" on Mac with MAMP 2.2

Issue

When trying to run a rails server in my current directory (which is a new rails project), it says that I need to install the mysql2 gem. At first, I had no idea what this meant... Then, I did some poking around, and finally decided to install the gem. However, I am getting this super pesky error (seeing as I just spent 2 hours trying to investigate, and solve another error). I am on the brink of giving up, but I really want to try rails. Please help!

Currently, if I run sudo gem install mysql2, or even as some people told me to do online, gem install mysql -- \ --with-mysql-config=/Applications/MAMP/Library/bin/mysql_config (I have MAMP), it gives me the following error:

Building native extensions.  This could take a while...
ERROR:  Error installing mysql2:
    ERROR: Failed to build gem native extension.

    /Users/vicky/.rvm/rubies/ruby-2.0.0-p247/bin/ruby extconf.rb
checking for ruby/thread.h... yes
checking for rb_thread_call_without_gvl() in ruby/thread.h... yes
checking for rb_thread_blocking_region()... yes
checking for rb_wait_for_single_fd()... yes
checking for rb_hash_dup()... yes
checking for rb_intern3()... yes
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Using mysql_config at /Applications/MAMP/Library/bin/mysql_config
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checking for mysql.h... yes
checking for errmsg.h... yes
checking for mysqld_error.h... yes
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Don't know how to set rpath on your system, if MySQL libraries are not in path mysql2 may not load
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Setting libpath to /Applications/MAMP/Library/lib
-----
creating Makefile

make "DESTDIR="
compiling client.c
compiling mysql2_ext.c
compiling result.c
linking shared-object mysql2/mysql2.bundle
ld: warning: directory not found for option '-L/Users/mpapis/.sm/pkg/active/lib'
ld: library not found for -lmysqlclient
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [mysql2.bundle] Error 1


Gem files will remain installed in /Users/username/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/gems/2.0.0/gems/mysql2-0.3.14 for inspection.
Results logged to /Users/username/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/gems/2.0.0/gems/mysql2-0.3.14/ext/mysql2/gem_make.out

Solution

Have you considered installing MySQL with homebrew (http://brew.sh/)? MAMP stands for Mac-Apache-MySQL-PHP (the last part of this being the most important). I would suggest just installing MySQL directly on your box (homebrew takes care of all the heavy lifting) and afterwards I doubt you'll have any difficulty installing that gem.

To install homebrew --

ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)"

Run brew doctor follow any instructions and then afterwards to install MySQL run brew install mysql and follow any of the instructions it provides for setting up a user, etc...

============= UPDATE ==============

SO, what you'll want to do is use brew this way to install MySQL and then install the gem in the normal fashion - sudo gem install mysql2 assuming this works, then you will be able to switch back to the old MySQL install through MAMP via -

sudo nano /etc/paths

then add this line to the top of the document -

/Applications/MAMP/Library/bin

restart your terminal and then run mysql to double check that you are using the MAMP installation of MySQL, and you'll be good to go.

Answered By - Noah Davis