installing ruby gems on opensuse runs into issues .. need help

[sayhello]

hello dear linux experts

while installing ruby-gems i run into issues

Code:
linux-70ce:/home/martin/perl # ^C
linux-70ce:/home/martin/perl # gem install mysql2
Fetching: mysql2-0.3.16.gem (100%)
Building native extensions. This could take a while...
ERROR: Error installing mysql2:
ERROR: Failed to build gem native extension.

/usr/bin/ruby2.0 extconf.rb
mkmf.rb can't find header files for ruby at /usr/lib/ruby/include/ruby.h


Gem files will remain installed in /usr/lib/ruby/gems/2.0.0/gems/mysql2-0.3.16 for inspection.
Results logged to /usr/lib/ruby/gems/2.0.0/gems/mysql2-0.3.16/ext/mysql2/gem_make.out
linux-70ce:/home/martin/perl # ^C
linux-70ce:/home/martin/perl # ^C
linux-70ce:/home/martin/perl # ^C
linux-70ce:/home/martin/perl # gem install sequel

Fetching: sequel-4.11.0.gem (100%)
Successfully installed sequel-4.11.0
Parsing documentation for sequel-4.11.0
Installing ri documentation for sequel-4.11.0
1 gem installed
linux-70ce:/home/martin/perl #
linux-70ce:/home/martin/perl # gem install mysql
Fetching: mysql-2.9.1.gem (100%)
Building native extensions. This could take a while...
ERROR: Error installing mysql:
ERROR: Failed to build gem native extension.

/usr/bin/ruby2.0 extconf.rb
mkmf.rb can't find header files for ruby at /usr/lib/ruby/include/ruby.h


Gem files will remain installed in /usr/lib/ruby/gems/2.0.0/gems/mysql-2.9.1 for inspection.
Results logged to /usr/lib/ruby/gems/2.0.0/gems/mysql-2.9.1/ext/mysql_api/gem_make.out
linux-70ce:/home/martin/perl #
i have no glue what happens here

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