sudo gem install mysql

W czasie instalacji gema mysql pojawia się błąd

sudo gem install mysql


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

/usr/bin/ruby1.8 extconf.rb
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lm... yes
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... yes
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lmygcc... 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=/usr/bin/ruby1.8
 --with-mysql-config
 --without-mysql-config
 --with-mysql-dir
 --without-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
 --with-mygcclib
 --without-mygcclib
 --with-mysqlclientlib
 --without-mysqlclientlib


Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/mysql-2.8.1 for inspection.
Results logged to /usr/lib/ruby/gems/1.8/gems/mysql-2.8.1/ext/mysql_api/gem_make.out

By tego uniknąć trzeba zainstalować bibliotekę libmysqlclient15-dev.

sudo apt-get install libmysqlclient15-dev 

I potem gem mysql instaluje się bez problemu.

sudo gem install mysql

Building native extensions.  This could take a while...
Successfully installed mysql-2.8.1
1 gem installed
Installing ri documentation for mysql-2.8.1...
Updating ri class cache with 2014 classes...
Installing RDoc documentation for mysql-2.8.1...