ruby-on-rails – 在rails 3中未发现rake任务

耙宝石：安装

rake aborted!
Don't know how to build task 'gems:install'

耙-T

rake about              # List versions of all Rails frameworks and the environment
rake db:create          # Create the database from config/database.yml for the current Rails.env (use db:create:all to create all dbs in the config)
rake db:drop            # Drops the database for the current Rails.env (use db:drop:all to drop all databases)
rake db:fixtures:load   # Load fixtures into the current environment's database.
rake db:migrate         # Migrate the database (options: VERSION=x,VERBOSE=false).
rake db:migrate:status  # Display status of migrations
rake db:rollback        # Rolls the schema back to the previous version (specify steps w/ STEP=n).
rake db:schema:dump     # Create a db/schema.rb file that can be portably used against any DB supported by AR
rake db:schema:load     # Load a schema.rb file into the database
rake db:seed            # Load the seed data from db/seeds.rb
rake db:setup           # Create the database,load the schema,and initialize with the seed data (use db:reset to also drop the db first)
rake db:structure:dump  # Dump the database structure to an SQL file
rake db:version         # Retrieves the current schema version number
rake doc:app            # Generate docs for the app -- also availble doc:rails,doc:guides,doc:plugins (options: TEMPLATE=/rdoc-template.rb,TITLE="Custom Title")
rake log:clear          # Truncates all *.log files in log/ to zero bytes
rake middleware         # Prints out your Rack middleware stack
rake notes              # Enumerate all annotations (use notes:optimize,:fixme,:todo for focus)
rake notes:custom       # Enumerate a custom annotation,specify with ANNOTATION=CUSTOM
rake rails:template     # Applies the template supplied by LOCATION=/path/to/template
rake rails:update       # Update both configs and public/javascripts from Rails (or use just update:javascripts or update:configs)
rake routes             # Print out all defined routes in match order,with names.
rake secret             # Generate a crytographically secure secret key (this is typically used to generate a secret for cookie sessions).
rake stats              # Report code statistics (KLOCs,etc) from the application
rake test               # Runs test:units,test:functionals,test:integration together (also available: test:benchmark,test:profile,test:plugins)
rake test:recent        # Run tests for recenttest:prepare / Test recent changes
rake test:uncommitted   # Run tests for uncommittedtest:prepare / Test changes since last checkin (only Subversion and Git)
rake time:zones:all     # Displays all time zones,also available: time:zones:us,time:zones:local -- filter with OFFSET parameter,e.g.,OFFSET=-6
rake tmp:clear          # Clear session,cache,and socket files from tmp/ (narrow w/ tmp:sessions:clear,tmp:cache:clear,tmp:sockets:clear)
rake tmp:create         # Creates tmp directories for sessions,sockets,and pids

所以问题是,没有包含宝石任务.
这可能也是原因,我无法安装指南针.它给了我以下错误：

rails new testproj -m http://compass-style.org/rails/installer

rake    gems:install GEM=haml --trace
rake aborted!
Don't know how to build task 'gems:install'

打包机在我的系统上坏了吗？我在雪豹上.