Travis Build Failing on Jekyll Project - Cannot Find Jekyll?

Question

Observe from the below log that Jekyll is installing, but yet the error states it can't be found. It is unclear to me why this is unable to find Jekyll - do I need to state a more explicit path? The docs on Jekyll's website give no indication as to why this might be occurring, but I feel it's something simple I'm not comprehending.

Using worker: worker-linux-027f0490-2.bb.travis-ci.org:travis-linux-16

Build system information
Build language: ruby
Build image provisioning date and time
Wed Feb  4 18:22:50 UTC 2015
Operating System Details
Distributor ID: Ubuntu
Description:    Ubuntu 12.04 LTS
Release:    12.04
Codename:   precise
Linux Version
2.6.32-042stab090.5
Cookbooks Version
23bb455 https://github.com/travis-ci/travis-cookbooks/tree/23bb455
GCC version
gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3
Copyright (C) 2011 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

LLVM version
clang version 3.4 (tags/RELEASE_34/final)
Target: x86_64-unknown-linux-gnu
Thread model: posix
Pre-installed Ruby versions
ruby-1.9.3-p551
Pre-installed Node.js versions
v0.10.36
Pre-installed Go versions
1.4.1
Redis version
redis-server 2.8.19
riak version
2.0.2
MongoDB version
MongoDB 2.4.12
CouchDB version
couchdb 1.6.1
Neo4j version
1.9.4
Cassandra version
2.0.9
RabbitMQ Version
3.4.3
ElasticSearch version
1.4.0
Installed Sphinx versions
2.0.10
2.1.9
2.2.6
Default Sphinx version
2.2.6
Installed Firefox version
firefox 31.0esr
PhantomJS version
1.9.8
ant -version
Apache Ant(TM) version 1.8.2 compiled on December 3 2011
mvn -version
Apache Maven 3.2.5 (12a6b3acb947671f09b81f49094c53f426d8cea1; 2014-12-14T17:29:23+00:00)
Maven home: /usr/local/maven
Java version: 1.7.0_76, vendor: Oracle Corporation
Java home: /usr/lib/jvm/java-7-oracle/jre
Default locale: en, platform encoding: UTF-8
OS name: "linux", version: "2.6.32-042stab090.5", arch: "amd64", family: "unix"

$ git clone --depth=50 --branch=master git://github.com/tohuw/tohuw.net.git tohuw/tohuw.net
Cloning into 'tohuw/tohuw.net'...
remote: Counting objects: 167, done.
remote: Compressing objects: 100% (132/132), done.
remote: Total 167 (delta 70), reused 121 (delta 27)
Receiving objects: 100% (167/167), 77.91 KiB | 0 bytes/s, done.
Resolving deltas: 100% (70/70), done.
Checking connectivity... done.
$ cd tohuw/tohuw.net
$ git checkout -qf 6c202bf02ffaf730ea9b58b5b7df72a1b5c12e55

Setting environment variables from .travis.yml
$ export NOKOGIRI_USE_SYSTEM_LIBRARIES=true

$ rvm use 2.2.0 --install --binary --fuzzy
Using /home/travis/.rvm/gems/ruby-2.2.0
$ export BUNDLE_GEMFILE=$PWD/Gemfile
$ ruby --version
ruby 2.2.0p0 (2014-12-25 revision 49005) [x86_64-linux]
$ rvm --version
rvm 1.26.10 (latest-minor) by Wayne E. Seguin <wayneeseguin@gmail.com>, Michal Papis <mpapis@gmail.com> [https://rvm.io/]
$ bundle --version
Bundler version 1.7.9
$ gem --version
2.4.5
$ bundle install --jobs=3 --retry=3 --deployment
Fetching gem metadata from https://rubygems.org/.......
Installing blankslate 2.1.2.4
Installing addressable 2.3.7
Installing chunky_png 1.3.4
Installing fast-stemmer 1.0.2
Installing hitimes 1.2.2
Installing coffee-script-source 1.9.0
Installing execjs 2.3.0
Installing colorator 0.1
Installing colored 1.2
Installing multi_json 1.10.1
Installing rb-fsevent 0.9.4
Installing sass 3.4.12
Installing mercenary 0.3.5
Installing mini_portile 0.6.2
Installing parallel 1.4.0
Installing yell 2.0.5
Installing jekyll-gist 1.1.0
Installing jekyll-paginate 1.1.0
Installing kramdown 1.5.0
Installing liquid 2.6.2
Installing posix-spawn 0.3.9
Installing yajl-ruby 1.2.1
Installing ffi 1.9.6
Installing safe_yaml 1.0.4
Installing rainbow 2.0.0
Installing rouge 1.8.0
Using bundler 1.7.9
Installing parslet 1.5.0
Installing classifier-reborn 2.0.3
Installing redcarpet 3.2.2
Installing timers 4.0.1
Installing coffee-script 2.3.0
Installing compass-import-once 1.0.5
Installing compass-core 1.0.3
Installing font-awesome-sass 4.3.1
Installing jekyll-sass-converter 1.3.0
Installing pygments.rb 0.6.2
Installing rb-inotify 0.9.5
Installing ethon 0.7.2
Installing scss-lint 0.33.0
Installing toml 0.1.2
Installing celluloid 0.16.0
Installing jekyll-coffeescript 1.0.1
Installing compass 1.0.3
Installing typhoeus 0.7.1
Installing listen 2.8.5
Installing compass-html5bp 1.0.0
Installing jekyll-watch 1.2.1
Installing jekyll 2.5.3
Installing nokogiri 1.6.6.2
Installing html-proofer 2.1.0
Your bundle is complete!
It was installed into ./vendor/bundle
Post-install message from compass:
    Compass is charityware. If you love it, please donate on our behalf at http://umdf.org/compass Thanks!
$ jekyll build
/home/travis/build.sh: line 41: jekyll: command not found

The command "jekyll build" exited with 127.

Done. Your build exited with 1.

My .travis.yml :

language: ruby
rvm:
- 2.2.0
script: jekyll build

env:
  global:
  - NOKOGIRI_USE_SYSTEM_LIBRARIES=true

Answer 1

I changed the script: command like thus:

script: bundle exec jekyll build

I realized I should do this because the log told me that...

Your bundle is complete!
It was installed into ./vendor/bundle

I realized it was quite unlikely such a location would automatically appear in $PATH , and that bundle exec was made for this sort of thing. Easy answer, but I'll leave this around in case some other neophyte has a similar issue.