Superclass mismatch with Rails 3

Rails
1

I’m currently developing a Rails 2 project that I’d like to migrate
across to Rail 3. However I’m having real trouble in the first place
getting Rails 3 to work straight out of the box with a blank project.

Initially I tried getting this working a JRuby 1.5 snapshot & then 1.4.
I’ve now been trying the same with Ruby 1.9.1-p378-rc2 from
RubyInstaller with the same results.

The error:
Upon executing “ruby script\rails server” (rails server doesn’t work in
Windows. Running Win7 btw) I always get the following error…

C:\Users\Phil O.\Desktop\Project\Rails>ruby script\rails server

C:/Users/Phil O./Desktop/Project/Rails/config/application.rb:9:in
<module:Rails>': superclass mismatch for class Application (TypeError) from C:/Users/Phil Ostler/Desktop/Project/Rails/config/application.rb:8:in<top
(required)>’
from
C:/Ruby19/lib/ruby/gems/1.9.1/gems/railties-3.0.0.beta/lib/rails/co
mmands.rb:36:in require' from C:/Ruby19/lib/ruby/gems/1.9.1/gems/railties-3.0.0.beta/lib/rails/co mmands.rb:36:in<top (required)>’
from script/rails:10:in require' from script/rails:10:in’

I’ve tried using the latest gems as well as following any guides I could
find and matching the gem versions they used but always get the same
result.

Current local gem list:
*** LOCAL GEMS ***
abstract (1.0.0)
actionmailer (3.0.0.beta)
actionpack (3.0.0.beta)
activemodel (3.0.0.beta)
activerecord (3.0.0.beta)
activeresource (3.0.0.beta)
activesupport (3.0.0.beta, 2.3.5)
arel (0.2.1)
builder (2.1.2)
bundler (0.9.10)
erubis (2.6.5)
i18n (0.3.5)
mail (2.1.3)
memcache-client (1.7.8)
mime-types (1.16)
polyglot (0.3.1)
rack (1.1.0)
rack-mount (0.6.0, 0.4.7)
rack-test (0.5.3)
rails (3.0.0.beta)
railties (3.0.0.beta)
rake (0.8.7)
rubygems-update (1.3.6)
text-format (1.0.0)
text-hyphen (1.0.0)
thor (0.13.4)
treetop (1.4.5)
tzinfo (0.3.16)

I’ve googled this and vaguely understand the error but don’t know how to
go about fixing it. I get the feeling this might not be my setup and
more a gem that’s breaking Rail 3 but that could be miles off the mark.

Any suggestions?

Cheers, Phil

2

“Phil O.” [email protected] wrote in
message news:[email protected]…

I’m currently developing a Rails 2 project that I’d like to migrate
across to Rail 3. However I’m having real trouble in the first place
getting Rails 3 to work straight out of the box with a blank project.

First a hint. There is a gem named rails3b that somebody in the rails
core
team created to pull in the missing dependecies of the Rails gem when
using
the rails 3 beta.

Second, Your problem is naming the test application “Rails”. That
results in
a module named “Rails” that contains your application, but the Rails
module
is part of Rails’ own namespace.

Thus your config/application.rb is trying to create or re-open a
Rails::Application class that is derived from Rails::Application. I’m
not an
expert in that corner of Ruby, but I’m not sure tryingg to have a class
derive from itself could ever be expected to work. Further
Rails::Application is already defined, and it has a different base
class, so
ruby has no idea what to do, so it spits out an error and stops.

Try creating a project with a unique name. You should probably find that
works better.

3

Indeed you are right, changing the name of my application has fixed
this. Thank you!

Reason for me naming it Rails is because I have separate folders in my
project development for different elements (e.g. Rails, Database Schema,
Flex) and it always worked in Rails 2 fine for me this way.

I’ve used rails3b before but was mix and matching gem versions to try
and get around this problem.

Now running Ruby 1.9.1-p378-rc2 with Rails 3.0.0.beta2!

Next stop, JRuby 1.5.0 dev snapshot…

Cheers!

4

On Fri, Apr 2, 2010 at 8:02 AM, Phil O. [email protected]
wrote:

Now running Ruby 1.9.1-p378-rc2 with Rails 3.0.0.beta2!
From what I’ve read 1.9.1 is NOT recommended for use with Rails3 beta
2, they want us to use the latest pre-release version of 1.9.2
instead.
–
Rick DeNatale

Blog: http://talklikeaduck.denhaven2.com/
Github: rubyredrick (Rick DeNatale) · GitHub
Twitter: @RickDeNatale
WWR: http://www.workingwithrails.com/person/9021-rick-denatale
LinkedIn: http://www.linkedin.com/in/rickdenatale