[ruby-it] gem mysql con rails 2.3.3 ruby 1.9.1-p129

[Sergio]

non riesco ad installare gem install mysql su xp !!!!!

comando: gem install mysql

errore: >>>>>>>



C:\Documents and Settings\Sergio>gem install mysql
Building native extensions.  This could take a while...
ERROR:  Error installing mysql:
        ERROR: Failed to build gem native extension.

c:/ruby191/bin/ruby.exe extconf.rb
checking for mysql_query() in -lmysqlclient... *** 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=c:/ruby191/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
c:/ruby191/lib/ruby/1.9.1/mkmf.rb:362:in `try_do': The complier failed 
to genera
te an executable file. (RuntimeError)
You have to install development tools first.
        from c:/ruby191/lib/ruby/1.9.1/mkmf.rb:415:in `try_link0'
        from c:/ruby191/lib/ruby/1.9.1/mkmf.rb:419:in `try_link'
        from c:/ruby191/lib/ruby/1.9.1/mkmf.rb:527:in `try_func'
        from c:/ruby191/lib/ruby/1.9.1/mkmf.rb:748:in `block in 
find_library'
        from c:/ruby191/lib/ruby/1.9.1/mkmf.rb:668:in `block in 
checking_for'
        from c:/ruby191/lib/ruby/1.9.1/mkmf.rb:274:in `block (2 levels) 
in postp
one'
        from c:/ruby191/lib/ruby/1.9.1/mkmf.rb:248:in `open'
        from c:/ruby191/lib/ruby/1.9.1/mkmf.rb:274:in `block in postpone'
        from c:/ruby191/lib/ruby/1.9.1/mkmf.rb:248:in `open'
        from c:/ruby191/lib/ruby/1.9.1/mkmf.rb:270:in `postpone'
        from c:/ruby191/lib/ruby/1.9.1/mkmf.rb:667:in `checking_for'
        from c:/ruby191/lib/ruby/1.9.1/mkmf.rb:744:in `find_library'
        from extconf.rb:14:in `<main>'


Gem files will remain installed in 
c:/ruby191/lib/ruby/gems/1.9.1/gems/mysql-2.7
 for inspection.
Results logged to c:/ruby191/lib/ruby/gems/1.9.1/gems/mysql-2.7/gem_make.out

C:\Documents and Settings\Sergio>


Qualcuno ha una spiegazione ?????
Credo sia il percorso delle librerie di mysql.

Grazie per suggerimenti,
Saluti,
Sergio.