How to install mysql2 gem in Ubuntu

Got an error message when you install the mysql2 gem in Ubuntu? Before you install mysql2, make sure you have libmysqlclient-dev installed or you’ll get the following:

[code lang=”bash”]kahwee@kahwee-desktop:/$ gem install mysql2
Building native extensions. This could take a while…
ERROR: Error installing mysql2:
ERROR: Failed to build gem native extension.

/home/kahwee/.rvm/rubies/ruby-1.9.2-p0/bin/ruby extconf.rb
checking for rb_thread_blocking_region()… yes
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… yes
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=/home/kahwee/.rvm/rubies/ruby-1.9.2-p0/bin/ruby
–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 /home/kahwee/.rvm/gems/ruby-1.9.2-p0/gems/mysql2-0.2.6 for inspection.
Results logged to /home/kahwee/.rvm/gems/ruby-1.9.2-p0/gems/mysql2-0.2.6/ext/mysql2/gem_make.out[/code]

To resolve it, install libmysqlclient-dev:

[code lang=”bash”]sudo apt-get install libmysqlclient-dev[/code]

And now you can install mysql2 successful:

[code lang=”bash”]kahwee@kahwee-desktop:/$ gem install mysql2
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…
Installing RDoc documentation for mysql2-0.2.6…[/code]

Great!

[I tried this on Ubuntu 10.10.]

How to install pg gem for PostgreSQL in Ubuntu

I am using PostgreSQL 8.4 in Ubuntu 10.10.

After install postgresql-8.4 with aptitude in Ubuntu, I couldn’t seem to get the pg gem (postgres) to install right. It has the following error:

[code lang=”bash”]$ gem install pg
Building native extensions. This could take a while…
ERROR: Error installing pg:
ERROR: Failed to build gem native extension.

/home/kahwee/.rvm/rubies/ruby-1.9.2-head/bin/ruby extconf.rb
checking for pg_config… no
checking for libpq-fe.h… no
Can’t find the ‘libpq-fe.h header
*** 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=/home/kahwee/.rvm/rubies/ruby-1.9.2-head/bin/ruby
–with-pg
–without-pg
–with-pg-config
–without-pg-config
–with-pg-dir
–without-pg-dir
–with-pg-include
–without-pg-include=${pg-dir}/include
–with-pg-lib
–without-pg-lib=${pg-dir}/lib
–enable-static-build
–disable-static-build

Gem files will remain installed in /home/kahwee/.rvm/gems/ruby-1.9.2-head/gems/pg-0.9.0 for inspection.
Results logged to /home/kahwee/.rvm/gems/ruby-1.9.2-head/gems/pg-0.9.0/ext/gem_make.out[/code]

I already have libpq5 installed but I realized what I needed in libpq-dev.

[code lang=”bash”]sudo apt-get install libpq-dev[/code]

After installing, run “gem install pg” again:

[code lang=”bash”]$ gem install pg
Building native extensions. This could take a while…
Successfully installed pg-0.9.0
1 gem installed
Installing ri documentation for pg-0.9.0…
Installing RDoc documentation for pg-0.9.0…[/code]

And success.