libcurl on Windows problems

I am having a hard time installing libcurl ruby bindings gem (curb) on Windows. I have done everything right. I have libcurl directory on the PATH, and then I try two ways of installing the gem

gem install curb

and

rake install EXTCONF_OPTS='--with-curl-dir=B:\curl'

None of them work. They fail with different errors, though, and the second one's error is more constructive:

C:/Ruby/lib/ruby/gems/1.8/gems/curb-0.7.7.1/ext/curb_postfield.c:76: undefined reference to 'imp_curl_formadd'

But I don't know what this means.

EDIT: The first error is this complaint

extconf.rb:19: Can't find libcurl or 开发者_如何学Pythoncurl/curl.h (RuntimeError)

Even though libcurl dir (B:\curl) is already in the PATH. Here is the full error message--I put it ina gist because the formatting was too weird for this place.

picardo,

I've had trouble installing the curb gem in Windows before. In trying to see how others had solved this I came across a lot of questions and not very many solutions. Having to do it again tonight I decided to document my steps and post the results: http://beginrescue.blogspot.com/2010/07/installing-curb-with-ruby-191-in.html

Sorry for the blogspam, hope this is useful for somebody.

pete