Background
I updated the Jekyll-Bootstrap source code for Blog 2.
Problem
Then, I wanted to preview it.
[owner@localhost ~/blog2]$ jekyll serve
/home/owner/.rvm/gems/ruby-2.1.2@global/gems/bundler-1.6.5/lib/bundler/resolver.
rb:357:in `resolve': Could not find gem 'jekyll (~> 3.1) ruby' in the gems avail
able on this machine. (Bundler::GemNotFound)
from /home/owner/.rvm/gems/ruby-2.1.2@global/gems/bundler-1.6.5/lib/bund
ler/resolver.rb:164:in `start'
from /home/owner/.rvm/gems/ruby-2.1.2@global/gems/bundler-1.6.5/lib/bund
ler/resolver.rb:129:in `resolve'
from /home/owner/.rvm/gems/ruby-2.1.2@global/gems/bundler-1.6.5/lib/bund
ler/definition.rb:203:in `resolve'
from /home/owner/.rvm/gems/ruby-2.1.2@global/gems/bundler-1.6.5/lib/bund
ler/definition.rb:133:in `specs'
from /home/owner/.rvm/gems/ruby-2.1.2@global/gems/bundler-1.6.5/lib/bund
ler/definition.rb:178:in `specs_for'
from /home/owner/.rvm/gems/ruby-2.1.2@global/gems/bundler-1.6.5/lib/bund
ler/definition.rb:167:in `requested_specs'
from /home/owner/.rvm/gems/ruby-2.1.2@global/gems/bundler-1.6.5/lib/bund
ler/environment.rb:18:in `requested_specs'
from /home/owner/.rvm/gems/ruby-2.1.2@global/gems/bundler-1.6.5/lib/bund
ler/runtime.rb:13:in `setup'
from /home/owner/.rvm/gems/ruby-2.1.2@global/gems/bundler-1.6.5/lib/bund
ler.rb:120:in `setup'
from /home/owner/.rvm/gems/ruby-2.1.2/gems/jekyll-2.5.3/lib/jekyll/plugi
n_manager.rb:37:in `require_from_bundler'
from /home/owner/.rvm/gems/ruby-2.1.2/gems/jekyll-2.5.3/bin/jekyll:16:in
`<top (required)>'
from /home/owner/.rvm/gems/ruby-2.1.2/bin/jekyll:23:in `load'
from /home/owner/.rvm/gems/ruby-2.1.2/bin/jekyll:23:in `<main>'
from /home/owner/.rvm/gems/ruby-2.1.2/bin/ruby_executable_hooks:15:in `e
val'
from /home/owner/.rvm/gems/ruby-2.1.2/bin/ruby_executable_hooks:15:in `<
main>'
How can it be previewed?
N.B. I replaced all tabs with spaces due to a remark of my article Recent Vundle Plugin Update.
Solution
From the head of the error message, it’s reasonable to guess that the outdated Ruby gems were the cause.
[owner@localhost ~/blog2]$ gem update
Updating installed gems
Updating RedCloth
Fetching: RedCloth-4.3.2.gem (100%)
Building native extensions. This could take a while...
Successfully installed RedCloth-4.3.2
Updating bigdecimal
Fetching: bigdecimal-1.2.7.gem (100%)
Building native extensions. This could take a while...
Successfully installed bigdecimal-1.2.7
Updating blankslate
Fetching: blankslate-3.1.3.gem (100%)
Successfully installed blankslate-3.1.3
Updating bundler
Fetching: bundler-1.12.5.gem (100%)
Successfully installed bundler-1.12.5
Updating celluloid
Fetching: timers-4.1.1.gem (100%)
Successfully installed timers-4.1.1
Fetching: celluloid-essentials-0.20.5.gem (100%)
Successfully installed celluloid-essentials-0.20.5
Fetching: celluloid-supervision-0.20.6.gem (100%)
Successfully installed celluloid-supervision-0.20.6
Fetching: celluloid-pool-0.20.5.gem (100%)
Successfully installed celluloid-pool-0.20.5
Fetching: celluloid-fsm-0.20.5.gem (100%)
Successfully installed celluloid-fsm-0.20.5
Fetching: celluloid-extras-0.20.5.gem (100%)
Successfully installed celluloid-extras-0.20.5
Fetching: celluloid-0.17.3.gem (100%)
Successfully installed celluloid-0.17.3
Updating chunky_png
Fetching: chunky_png-1.3.6.gem (100%)
Successfully installed chunky_png-1.3.6
Updating classifier-reborn
Fetching: classifier-reborn-2.0.4.gem (100%)
Successfully installed classifier-reborn-2.0.4
Updating coffee-script
Fetching: coffee-script-2.4.1.gem (100%)
Successfully installed coffee-script-2.4.1
Updating coffee-script-source
Fetching: coffee-script-source-1.10.0.gem (100%)
Successfully installed coffee-script-source-1.10.0
Updating colorator
Fetching: colorator-1.1.0.gem (100%)
Successfully installed colorator-1.1.0
Updating domain_name
Fetching: domain_name-0.5.20160615.gem (100%)
Successfully installed domain_name-0.5.20160615
Updating execjs
Fetching: execjs-2.7.0.gem (100%)
Successfully installed execjs-2.7.0
Updating ffi
Fetching: ffi-1.9.14.gem (100%)
Building native extensions. This could take a while...
Successfully installed ffi-1.9.14
Updating gem-wrappers
Fetching: gem-wrappers-1.2.7.gem (100%)
Building native extensions. This could take a while...
Successfully installed gem-wrappers-1.2.7
Updating haml
Fetching: haml-4.0.7.gem (100%)
HEADS UP! Haml 4.0 has many improvements, but also has changes that may break
your application:
* Support for Ruby 1.8.6 dropped
* Support for Rails 2 dropped
* Sass filter now always outputs <style> tags
* Data attributes are now hyphenated, not underscored
* html2haml utility moved to the html2haml gem
* Textile and Maruku filters moved to the haml-contrib gem
For more info see:
http://rubydoc.info/github/haml/haml/file/CHANGELOG.md
Successfully installed haml-4.0.7
Updating hitimes
Fetching: hitimes-1.2.4.gem (100%)
Building native extensions. This could take a while...
Successfully installed hitimes-1.2.4
Updating io-console
Fetching: io-console-0.4.6.gem (100%)
Building native extensions. This could take a while...
Successfully installed io-console-0.4.6
Updating jekyll
Fetching: liquid-3.0.6.gem (100%)
Successfully installed liquid-3.0.6
Fetching: rouge-1.11.1.gem (100%)
Successfully installed rouge-1.11.1
Fetching: forwardable-extended-2.6.0.gem (100%)
Successfully installed forwardable-extended-2.6.0
Fetching: pathutil-0.14.0.gem (100%)
Successfully installed pathutil-0.14.0
Fetching: jekyll-3.2.1.gem (100%)
Successfully installed jekyll-3.2.1
Updating jekyll-gist
Fetching: addressable-2.4.0.gem (100%)
Successfully installed addressable-2.4.0
Fetching: multipart-post-2.0.0.gem (100%)
Successfully installed multipart-post-2.0.0
Fetching: faraday-0.9.2.gem (100%)
Successfully installed faraday-0.9.2
Fetching: sawyer-0.7.0.gem (100%)
Successfully installed sawyer-0.7.0
Fetching: octokit-4.3.0.gem (100%)
Successfully installed octokit-4.3.0
Fetching: jekyll-gist-1.4.0.gem (100%)
Successfully installed jekyll-gist-1.4.0
Updating jekyll-sass-converter
Fetching: jekyll-sass-converter-1.4.0.gem (100%)
Successfully installed jekyll-sass-converter-1.4.0
Updating jekyll-sitemap
Fetching: jekyll-sitemap-0.11.0.gem (100%)
Successfully installed jekyll-sitemap-0.11.0
Updating jekyll-watch
Fetching: rb-inotify-0.9.7.gem (100%)
Successfully installed rb-inotify-0.9.7
Fetching: listen-3.0.8.gem (100%)
Successfully installed listen-3.0.8
Fetching: jekyll-watch-1.5.0.gem (100%)
Successfully installed jekyll-watch-1.5.0
Updating json
Fetching: json-2.0.2.gem (100%)
Building native extensions. This could take a while...
Successfully installed json-2.0.2
Updating kramdown
Fetching: kramdown-1.12.0.gem (100%)
Successfully installed kramdown-1.12.0
Updating mercenary
Fetching: mercenary-0.3.6.gem (100%)
Successfully installed mercenary-0.3.6
Updating mime-types
Fetching: mime-types-data-3.2016.0521.gem (100%)
Successfully installed mime-types-data-3.2016.0521
Fetching: mime-types-3.1.gem (100%)
Successfully installed mime-types-3.1
Updating mini_magick
Fetching: mini_magick-4.5.1.gem (100%)
Successfully installed mini_magick-4.5.1
Updating minitest
Fetching: minitest-5.9.0.gem (100%)
Successfully installed minitest-5.9.0
Updating multi_json
Fetching: multi_json-1.12.1.gem (100%)
Successfully installed multi_json-1.12.1
Updating octopress-date-format
Fetching: octopress-date-format-3.0.3.gem (100%)
Successfully installed octopress-date-format-3.0.3
Updating octopress-hooks
Fetching: octopress-hooks-2.6.1.gem (100%)
Successfully installed octopress-hooks-2.6.1
Updating parslet
Fetching: parslet-1.7.1.gem (100%)
Successfully installed parslet-1.7.1
Updating pdf-core
Fetching: pdf-core-0.6.1.gem (100%)
Successfully installed pdf-core-0.6.1
Updating posix-spawn
Fetching: posix-spawn-0.3.11.gem (100%)
Building native extensions. This could take a while...
Successfully installed posix-spawn-0.3.11
Updating prawn
Fetching: prawn-2.1.0.gem (100%)
Successfully installed prawn-2.1.0
Updating psych
Fetching: psych-2.1.0.gem (100%)
Building native extensions. This could take a while...
Successfully installed psych-2.1.0
Updating pygments.rb
Fetching: pygments.rb-0.6.3.gem (100%)
Successfully installed pygments.rb-0.6.3
Updating rack
Fetching: rack-2.0.1.gem (100%)
ERROR: Error installing rack:
rack requires Ruby version >= 2.2.2.
Updating rake
Fetching: rake-11.2.2.gem (100%)
Successfully installed rake-11.2.2
Updating rb-fsevent
Fetching: rb-fsevent-0.9.7.gem (100%)
Successfully installed rb-fsevent-0.9.7
Updating rdoc
Fetching: rdoc-4.2.2.gem (100%)
Depending on your version of ruby, you may need to install ruby rdoc/ri data:
<= 1.8.6 : unsupported
= 1.8.7 : gem install rdoc-data; rdoc-data --install
= 1.9.1 : gem install rdoc-data; rdoc-data --install
>= 1.9.2 : nothing to do! Yay!
Successfully installed rdoc-4.2.2
Updating redcarpet
Fetching: redcarpet-3.3.4.gem (100%)
Building native extensions. This could take a while...
Successfully installed redcarpet-3.3.4
Updating rest-client
Fetching: rest-client-2.0.0.gem (100%)
Successfully installed rest-client-2.0.0
Updating rubypants
Fetching: rubypants-0.5.0.gem (100%)
Successfully installed rubypants-0.5.0
Updating sass
Fetching: sass-3.4.22.gem (100%)
Successfully installed sass-3.4.22
Updating sass-globbing
Fetching: sass-globbing-1.1.5.gem (100%)
Successfully installed sass-globbing-1.1.5
Updating sinatra
Fetching: sinatra-1.4.7.gem (100%)
Successfully installed sinatra-1.4.7
Updating stringex
Fetching: stringex-2.6.1.gem (100%)
Successfully installed stringex-2.6.1
Updating test-unit
Fetching: power_assert-0.3.0.gem (100%)
Successfully installed power_assert-0.3.0
Fetching: test-unit-3.2.1.gem (100%)
Successfully installed test-unit-3.2.1
Updating tilt
Fetching: tilt-2.0.5.gem (100%)
Successfully installed tilt-2.0.5
Gems updated: RedCloth bigdecimal blankslate bundler celluloid celluloid-essenti
als celluloid-extras celluloid-fsm celluloid-pool celluloid-supervision timers c
hunky_png classifier-reborn coffee-script coffee-script-source colorator domain_
name execjs ffi gem-wrappers haml hitimes io-console forwardable-extended jekyll
liquid pathutil rouge addressable faraday jekyll-gist multipart-post octokit sa
wyer jekyll-sass-converter jekyll-sitemap jekyll-watch listen rb-inotify json kr
amdown mercenary mime-types mime-types-data mini_magick minitest multi_json octo
press-date-format octopress-hooks parslet pdf-core posix-spawn prawn psych pygme
nts.rb rack rake rb-fsevent rdoc redcarpet rest-client rubypants sass sass-globb
ing sinatra stringex power_assert test-unit tilt
[owner@localhost ~/blog2]$ jekyll serve
Configuration file: /home/owner/blog2/_config.yml
Source: /home/owner/blog2
Destination: /home/owner/blog2/_site
Incremental build: disabled. Enable with --incremental
Generating...
done in 1.135 seconds.
Auto-regeneration: enabled for '/home/owner/blog2'
Configuration file: /home/owner/blog2/_config.yml
Server address: http://127.0.0.1:4000/
Server running... press ctrl-c to stop.
[2016-08-18 19:19:37] ERROR `/favicon.ico' not found.
Due to the error on favicon.ico, I made commit 4aafebe.