NoMethodError: undefined method `fetch' for "QLite version 3.x":String - ruby-on-rails

Question

I am seeing this error when i am trying to deploy my rails app to production
SSHKit::Runner::ExecuteError: Exception while executing on host xxx.xxx.xxx.xx: rake exit status: 1
rake stdout: Nothing written
rake stderr: rake aborted!
NoMethodError: undefined method `fetch' for "QLite version 3.x":String
This error is invoked by th command
Command: cd /home/deploy/myapp/releases/20140616034148 && ( RAILS_ENV=production ~/.rvm/bin/rvm default do bundle exec rake assets:precompile )
capfile
# Load DSL and Setup Up Stages
require 'capistrano/setup'
# Includes default deployment tasks
require 'capistrano/deploy'
require 'capistrano/bundler'
require 'capistrano/rails'
require 'capistrano/rvm'
set :rvm_ruby_version, '2.1.2'
require 'capistrano/rails/assets'
require 'capistrano/rails/migrations'
deploy.rb
lock '3.1.0'
set :application, 'myapp'
set :repo_url, 'git#bitbucket.org:username/myapp.git'
set :deploy_to, '/home/deploy/myapp'
set :branch, "master"
set :linked_files, %w{config/database.yml}
set :linked_dirs, %w{bin log tmp/pids tmp/cache tmp/sockets vendor/bundle public/system}
namespace :deploy do
desc 'Restart application'
task :restart do
on roles(:app), in: :sequence, wait: 5 do
# Your restart mechanism here, for example:
execute :touch, release_path.join('tmp/restart.txt')
end
end
production.rb
set :stage, :production
role :app, %w{deploy#xxx.xxx.xxx.xx}
role :web, %w{deploy#xxx.xxx.xxx.xx}
role :db, %w{deploy#xxx.xxx.xxx.xx}
set :password, ask('Server password', nil)
server '107.170.187.98', user: 'deploy', password: fetch(:password), roles: %w{web app}
set :bundle_env_variables, { 'NOKOGIRI_USE_SYSTEM_LIBRARIES' => 1 }
I dont understand what is causing this issue. Can someone plz point me out in right direction.

Answer 1

Check the config/database.yml file you've set up on the production server. Its first line is probably "QLite version 3.x" - this is because it used to be "# SQLite version 3.x", but the initial "# S" has gone missing.
To fix this, just add the "# S" back to the front of it, or delete that line altogether. Once you've done that, your Capistrano deploy should start working again.
I'm guessing that you pasted your config/database.yml file from elsewhere into a Vim instance; I hit exactly the same problem as you did for exactly the same reason. If you don't put Vim into insert mode before you paste, it will paste the entire thing, but will drop the "# S" from the front.
The reason why these three in particular are deleted is because these letters are actually Vim commands. If you aren't in Insert mode, when you paste something, those commands will run. Those three characters, when pasted, do the following in sequence:
# - Moves the cursor to the previous occurrence of the last search. Since we didn't search for anything, nothing happens.
space - Moves the cursor to the right once. Since there's no content in the editor, nothing happens.
S - Deletes the number of lines there are before the S. Since there are no numbers before the S, nothing gets deleted. Once this is done, we enter Insert mode, and the rest of the document is pasted.
Source: http://vimdoc.sourceforge.net/htmldoc/