2010/5/14 Diego E. Petten<redmine / ruby-lang.org>:
> Bug #3294: [PATCH] Allow build of dbm extension with Berkeley DB 5.0 series
> http://redmine.ruby-lang.org/issues/show/3294
>
> Author: Diego E. Petten> Status: Open, Priority: Normal
> ruby -v: ruby 1.8.7 (2010-01-10 patchlevel 249) [x86_64-linux]
>
> In the new version of BerkDB, to use the DBM functions you need to definehe HAVE_DBM macro, otherwise the functions won't be defined (before, simply using DB_DBM_HSEARCH was enough). The attached patch enables that to make sure that it is possible to build the dbm extension properly.

What's exact version of Bereley DB?

I tested ruby 2.0.0dev (2011-11-11 trunk 33710) with
Berkeley DB 5.1 (Ubuntu package libdb5.1 version 5.1.25-11).
It works fine without your patch.
(The version of ruby don't define HAVE_DBM.)
-- 
Tanaka Akira