Comment 4 for bug 540193

This bug seems to be serious, it shows up on every new rails site created on an up to date Lucid Lynx:

rails test
cd test
scripts/server

Now if I open http://localhost:3000/ the first time, it works. But from then on, I only get Internal Server errors as "private method `gsub!' called for #<Class:0x7f6f1e0568d0>".

Changing res.set_error(err) to res.set_error(err.to_s) solved the problem for me.