Problem installing gems

I cannot install gem files on windows 7 running ruby 1.8.7
I tried to install watir-webdriver -v0.3.3 or selenium-webdriver -v0.2.2
but I got this message:

Building native extensions. This could take a while…
ERROR: Error installing watir-webdriver:
ERROR: Failed to build gem native extension.

    c:/ruby/bin/ruby.exe extconf.rb

checking for rb_thread_blocking_region()… no
checking for ruby_thread_has_gvl_p()… no
checking for ruby_native_thread_p()… no
checking for rb_thread_call_with_gvl()… no
creating extconf.h
creating Makefile

nmake
‘nmake’ is not recognized as an internal or external command,
operable program or batch file.

Gem files will remain installed in
c:/ruby/lib/ruby/gems/1.8/gems/ffi-1.0.9 for
inspection.
Results logged to
c:/ruby/lib/ruby/gems/1.8/gems/ffi-1.0.9/ext/ffi_c/gem_make.out

any idea how to solve this?

Thanks in advance

On Thu, Sep 15, 2011 at 08:06:31PM +0900, Mario R. wrote:

checking for ruby_thread_has_gvl_p()… no
checking for ruby_native_thread_p()… no
checking for rb_thread_call_with_gvl()… no
creating extconf.h
creating Makefile

nmake
‘nmake’ is not recognized as an internal or external command,
operable program or batch file.

nmake is the Micorosoft Visual Studio make tool. Do you have Visual
Studio installed?

On Thu, Sep 15, 2011 at 1:06 PM, Mario R. [email protected] wrote:

I cannot install gem files on windows 7 running ruby 1.8.7
I tried to install watir-webdriver -v0.3.3 or selenium-webdriver -v0.2.2
but I got this message:

Building native extensions. This could take a while…
ERROR: Error installing watir-webdriver:
ERROR: Failed to build gem native extension.

[snip]

any idea how to solve this?

http://rubyinstaller.org/add-ons/devkit/


Phillip G.

gplus.to/phgaw | twitter.com/phgaw

A method of solution is perfect if we can forsee from the start,
and even prove, that following that method we shall attain our aim.
– Leibniz