Having trouble getting iconv-0.5 working on OS X

I do a make, install, and then:

$ ruby -r iconv -e 'Iconv.iconv(“iso-8859-1”,“utf-8”, “hello”)'
dyld: ruby Undefined symbols:
_libiconv
_libiconv_close
_libiconv_open
Trace/BPT trap

It seems that ruby isn’t finding my /usr/local/lib/libiconv.dylib at
runtime, but I’m stumped as to how to convince it to look harder!

Does anybody have any suggestions?

Thanks,
Sam