Rails and readline problems on Mac OS X
If you build Ruby on Mac OS X yourself, you may face the following problem once you have downloaded the language's source from ruby-lang.org, compiled/installed it and tried to run your Rails app:
mike$ script/console
Loading development environment.
dyld: NSLinkModule() error
dyld: Symbol not found: _rl_filename_completion_function
Referenced from: /usr/local/lib/ruby/1.8/i686-darwin9.0.0b5/readline.bundle
Expected in: flat namespace
Trace/BPT trap
In order to fix the problem, you need to re-build readline from the source and then rebuild Ruby, linking it to the new readline's installation dir. Here's how you do it:
wget ftp://ftp.gnu.org/gnu/readline/readline-5.1.tar.gz
tar -xzf readline-5.1.tar.gz
cd readline-5.1
./configure –prefix=/usr/local && make && sudo make install
and then rebuild Ruby (you do it in your Ruby source directory of course)
make distclean && configure –with-readline-dir=/usr/local && make && make install
Once done, everything should be back on track.