Building First Filter Plugin

Elastic Stack Logstash
1

I am following along with the How to write a Logstash filter plugin, but when I get to the section for building, I'm getting an error:

$ build install
Fetching git://github.com/elastic/logstash.git
Fetching git://github.com/rest-client/rest-client.git
Fetching gem metadata from https://rubygems.org/........
Fetching version metadata from https://rubygems.org/..
Fetching dependency metadata from https://rubygems.org/.
Could not find gem 'logstash java' in git://github.com/elastic/logstash.git (at 5.2@81e342d).
Source does not contain any versions of 'logstash java'

Not sure what to do here. Any help is greatly appreciated.

2

I modified the Gemfile and it builds. This is my first Logstash plugin so I don't know if commenting out the "logstash" line is the right workaround.

$ cat Gemfile
source 'https://rubygems.org'                                                      
gemspec                                                                            
#gem "logstash", :github => "elastic/logstash", :branch => "5.2"                   
gem "rest-client", :github => "rest-client/rest-client", :branch => "2.0.x"

Did I break anything commenting out that line?