Here's an excerpt from a simple extconf.rb:

    have_header('antlr3.h')
    have_library('antlr3c', 'antlr3ParserNew')

The "have_library" line worked fine on the previous version of Mac OS
X (Tiger), but under Leopard it can't find the library. Output is:

    checking for antlr3ParserNew() in -lantlr3c... no

The library is definitely present at "/usr/local/lib/libantlr3c.a" and
inspection using the "nm" tool reveals that the "antlr3ParserNew"
symbol is definitely present in the library.

I've also tried using "find_library" with an explicit path to the
directory containing the library, and I've also tried making a dynamic
version of the library available instead of the static one, but mkmf
simply can't find the library.

Is there anyway I can get mkmf to be more verbose so that I can
diagnose what's happening here?

Best wishes,
Wincent