I had a problem running CouchDB from trunk as I followed the Wiki at http://wiki.apache.org/couchdb/Installing_on_OSX, getting an error message about the wrong architecture.
Turns out that the instructions for installing Erlang as 64bit and ICU in itself as 32bit was the problem. So re-making Erlang,
$ ./configure --enable-smp-support --enable-dynamic-ssl-lib --enable-kernel-poll --enable-darwin-64bit
TO
$ ./configure --enable-smp-support --enable-dynamic-ssl-lib --enable-kernel-poll --enable-darwin-32bit
resolved the issue and CouchDB ran without a hitch. (on Leopard)
