ReadLine

Readline requires some special configuration in order for it to build properly under darwin|macosx configurations.

% cd ~/build/
% curl -O ftp://ftp.cwru.edu/pub/bash/readline-4.3.tgz;
% gnutar xzf readline.*.tar.gz
% pushd readline-4.3/
Edit support/shobj-conf:
Inside the darwin*|macosx* configuration...
Replace:  SHLIB_LIBS='-lSystem'
With:     SHLIB_LIBS='-lSystem -lcurses -lgcc'
% ./configure --prefix=$LOCAL
% make
% sudo make install
% popd

Update: Readline version 5 and above build cleanly on the Mac.