Any ideas for a solution? Is it possible I have more than one
installation of ruby on my machine, with mongrel accessing the other
one? How do I find out and how do I resolve this?
That is possible. Look at the output of
which mongrel_rails
which gem
which ruby
which ruby => /usr/local/bin/ruby
which gem => /usr/local/bin/gem
which mongrel_rails => /usr/bin/mongrel_rails
What this means is that your ruby and gem commands were from the ruby
installation in /usr/local, which you have kept up to date (hence gem -
v returning 1.3.1) but the mongrel_rails command was part of the ruby
installation that came with OS X and was using the version of gem that
was part of that ruby installation, which happened to be an earlier
version. removing /usr/bin/mongrel_rails was actually unecessary -
installing mongrel will have created a /usr/local/bin/mongrel_rails
which would have taken precedence over the one in /usr/bin.