ERROR: 'rake/rdoctask' is obsolete and no longer supported. Use 'rdoc/task' (available in RDoc 2.4.2+) instead

Question

Seems the last post for this problem was closed for one reason or another so I'll try my luck...

I'm trying to run a simple "rake db:migrate" command. When I do, I get the error in the title. Yes, the solution "appears" obvious but it's not because I don't my Rakefile does not contain any references to 'rake/rdoctask'. It seems to be coming from documentation.rake but when I try to change that file as recommended by the error, I get a different error. I have found a couple of posts declaring this to be a known issue but nothing I've found indicates how to fix or work around this.

Does anyone have any ideas how to fix it? Below is the output from the rake command with a --trace:

$ rake --trace db:migrate
rake aborted!
ERROR: 'rake/rdoctask' is obsolete and no longer supported. Use 'rdoc/task' (available in RDoc 2.4.2+) instead.
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/rdoctask.rb:1:in `<top (required)>'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/tasks/documentation.rake:2:in `require'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/tasks/documentation.rake:2:in `<top (required)>'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/tasks.rb:15:in `load'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/tasks.rb:15:in `block in <top (required)>'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/tasks.rb:6:in `each'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/tasks.rb:6:in `<top (required)>'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/application.rb:213:in `require'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/application.rb:213:in `initialize_tasks'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/application.rb:139:in `load_tasks'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/application.rb:77:in `method_missing'
    C:/developer/skknobara/Rakefile:7:in `<top (required)>'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/rake_module.rb:25:in `load'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/rake_module.rb:25:in `load_rakefile'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:583:in `raw_load_rakefile'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:89:in `block in load_rakefile'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:160:in `standard_exception_handling'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:88:in `load_rakefile'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:72:in `block in run'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:160:in `standard_exception_handling'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:70:in `run'
    C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/bin/rake:33:in `<top (required)>'
    C:/Programs/Ruby193/bin/rake:23:in `load'
    C:/Programs/Ruby193/bin/rake:23:in `<main>'

---

I discovered that I had rails 3.0.3 in my Gemfile so I changed it to 3.2.9, but now when I run rake db:migrate I get:

rake aborted!
Bundler could not find compatible versions for gem "rack":
  In Gemfile:
    rails (= 3.2.9) x86-mingw32 depends on
      rack (~> 1.4.0) x86-mingw32

    rack (1.2.5)

I'm not sure what the error means but "gem list rack" shows I have both 1.4.1 and 1.4.0 installed. My Gemfile is pretty simple:

gem 'rails', '3.2.9'
gem 'rack','< 1.4.1'
gem 'mysql2', '< 0.3'

Any thoughts?

Answer 1

I had similar problem using rails 2.3.5 so as instructed in the trace message I have edited the Rakefile to require 'rdoc/task' instead of rake/rdoctask and installed rdoc gem.

If you are using rake version > 10.0.0 . please edit your Rakefile

from:

require 'rake'
require 'rake/testtask'
require 'rake/rdoctask'
require 'tasks/rails'

to:

require 'rake'
require 'rake/testtask'
require 'rdoc/task'
require 'tasks/rails'

If you don't want to edit the Rakefile you can switch back to older version of take like this

gem uninstall rake -v 10.0.3
gem install rake -v 0.8.7