gem install mysql2 fails - mysql

Question

I got this error:
sudo gem install mysql2
Building native extensions. This could take a while...
ERROR: Error installing mysql2:
ERROR: Failed to build gem native extension.
/usr/bin/ruby1.8 extconf.rb
checking for rb_thread_blocking_region()... no
checking for mysql.h... no
checking for mysql/mysql.h... no
-----
mysql.h is missing. please check your installation of mysql and try again.
-----
*** 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=/usr/bin/ruby1.8
--with-mysql-config
--without-mysql-config
Gem files will remain installed in /var/lib/gems/1.8/gems/mysql2-0.2.6 for inspection.
Results logged to /var/lib/gems/1.8/gems/mysql2-0.2.6/ext/mysql2/gem_make.out
I have tried:
uninstall mysql2 and install it again
uninstall mysql with apt-get
installd dev-tools from mysql
and almost all the pages on Google
How can I fix this?

Answer 1

You need to install libmysqlclient-dev before installing the mysql2 gem:
sudo apt-get install libmysqlclient-dev
gem install mysql2
This should fix this problem on the latest Ubuntu versions.

Answer 2

Thank Andre Schweighofer, just to it
sudo apt-get install libmysqlclient-dev
gem install mysql2
..
bundle update
bundle install
DONE !!!

Answer 3

It require to install mysql development package
yum install mysql-devel

Answer 4

Its helful to use the search here ;): ruby-mysql
here is another thread ;) with the same problem: ruby-mysql2
and many more when you search for "ruby mysql2" or something like this.

Answer 5

These are multiple causes of this failure :
Bad versions compatibility between ruby and rubygems
Missing libmysqlclient-dev
gem not locating the
Mysql 32bit on a 64 bit system
Solutions
Install rvm with latest stable release, You can switch after via rvm between ruby versions
curl -L https://get.rvm.io | bash -s stable
Install the dependecy
sudo apt-get install libmysqlclient-dev
locate mysql_config on your system (find / -name mysql_config) and run
gem install mysql -- --with-mysql-config=/path/to/mysql_config
Install the 64 bit version of mysql for your system

Answer 6

It could be due to mysql updated binary ( In my case it was using Mariadb-10.0.31) and on installing the missing library( libmysqlclient-dev ), I got the following message that it would be impossible to resolve:
$ sudo apt-get install libmysqlclient-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
libmysqlclient-dev : Depends: libmysqlclient18 (= 5.5.58-0ubuntu0.14.04.1)
But I resolved the above issue by first installing libmariadbclient-dev as:-
$ sudo apt-get install libmariadbclient-dev
It will install libmysqlclient-dev as well but by first resolving mariadb dependency.

Answer 7

On Ubuntu 10.10, I had to install libmysqlclient16-dev.

Answer 8

The way I solved was to inspect the mkmf.log, which in my case was somewhere in
./gems/ruby-2.2.3/extensions/x86_64-linux/2.2.0/mysql2-0.4.2/mkmf.log
In my case, there was an error that it could not find -lgmp, so it was missing the gmp library , so installed via apt-get , in this case libgmp-dev.