rake db:migrate rake aborted! unable to determine name from existing gemspec

Question

I am trying to rake db:migrate. I cloned a repository and tried to rake db:migrate, but get this error :

rake aborted!
Unable to determine name from existing gemspec. Use :name => 'gemname' in #inst
ll_tasks to manually set it. C:/Users/Dila/Documents/emo_project/Rakefile:6:in `<top (required)>'

In my Rakefile line 6, I have this :

require "bundler/gem_tasks"

This is what I got, when I trace it :

C:/Ruby193/lib/ruby/gems/1.9.1/gems/bundler-1.2.1/lib/bundler/gem_helper.rb:30:i
n `initialize'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/bundler-1.2.1/lib/bundler/gem_helper.rb:14:i
n `new'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/bundler-1.2.1/lib/bundler/gem_helper.rb:14:i
n `install_tasks'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/bundler-1.2.1/lib/bundler/gem_tasks.rb:2:in
`<top (required)>'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activesupport-3.2.2/lib/active_support/depen
dencies.rb:251:in `require'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activesupport-3.2.2/lib/active_support/depen
dencies.rb:251:in `block in require'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activesupport-3.2.2/lib/active_support/depen
dencies.rb:236:in `load_dependency'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activesupport-3.2.2/lib/active_support/depen
dencies.rb:251:in `require'
C:/Users/Dila/Documents/emo_project/Rakefile:6:in `<top (required)>'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/rake_module.rb:25:in `l
oad'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/rake_module.rb:25:in `l
oad_rakefile'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:589:in `
raw_load_rakefile'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:89:in `b
lock in load_rakefile'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:160:in `
standard_exception_handling'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:88:in `l
oad_rakefile'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:72:in `b
lock in run'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:160:in `
standard_exception_handling'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:70:in `r
un'
C:/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.4/bin/rake:33:in `<top (required)>
'
C:/Ruby193/bin/rake:23:in `load'
C:/Ruby193/bin/rake:23:in `<main>'

I have no idea what is went wrong, because yesterday I was working in my office and everything was ok. I just wanna try to clone the repository in my laptop, but it doesn't work.

my gemfile :

source 'https://rubygems.org'

if RUBY_VERSION =~ /1.9/
  Encoding.default_external = Encoding::UTF_8
  Encoding.default_internal = Encoding::UTF_8
end

group :production do
  gem 'pg', '0.12.2'
end

gem 'magic_encoding'

gem 'rails', '3.2.2'

# Bundle edge Rails instead:
# gem 'rails', :git => 'git://github.com/rails/rails.git'

gem 'sqlite3'

gem 'activeadmin'

gem "bcrypt-ruby", :require => "bcrypt"

# to copy to clipboard
gem 'zeroclipboard-rails'


# Gems used only for assets and not required
# in production environments by default.
group :assets do
  gem 'coffee-rails', '~> 3.2.1'

  # See https://github.com/sstephenson/execjs#readme for more supported runtimes
  #gem 'therubyracer'

  gem 'uglifier', '>= 1.0.4'
  gem 'sass-rails', '~> 3.2'
  gem 'bootstrap-sass', '~> 2.3.1.0'
  gem 'closure-compiler'

end

gem 'jquery-rails'

Answer 1

I see in your gemfile that you set postgresql as your production database, however you also set sqlite to run on production, test, and development.

group :production do
  gem 'pg', '0.12.2'
end

# Skip some lines to here

gem 'sqlite3'

I would make sure your database is uniform across the test, development, and production servers. I would remove sqlite3 and simply have

group :production do
  gem 'pg', '0.12.2'
end

replaced with

gem 'pg', '0.12.2'

That way, postgresql will run on all platforms. Or if your database.yml is connected to sqlite, then get rid of postgresql and keep the sqlite gem in your gemfile.