Redmine

When I was trying to execute 'rake generate_secret_token' on win 7 32 but system, encountered with mySql2.gem dependency. So executed undermentioned command but not able to install this gem. I am already done with Devkit & MySql connector stuffs. But still unable to install this gem.

C:\Webserver\Redmine>gem install mysql2 -v0.3.15
Temporarily enhancing PATH to include DevKit...
Building native extensions. This could take a while...
ERROR: Error installing mysql2:
ERROR: Failed to build gem native extension.

• 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.

C:/Webserver/Ruby/bin/ruby.exe 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
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... no
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lmygcc... no
checking for mysql_query() in -lmysqlclient... no

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=C:/Webserver/Ruby/bin/ruby
--with-mysql-dir
--without-mysql-dir
--with-mysql-include
--without-mysql-include=${mysql-dir}/include
--with-mysql-lib
--without-mysql-lib=${mysql-dir}/
--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}/
--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

extconf failed, exit code 1

Gem files will remain installed in C:/Webserver/Ruby/lib/ruby/gems/2.0.0/gems/mysql2-0.3.15 for inspection.
Results logged to C:/Webserver/Ruby/lib/ruby/gems/2.0.0/extensions/x86-mingw32/2.0.0/mysql2-0.3.15/gem_make.out

Now what should I do get things simpler.