Cannot install a local .gem

[mukarramali]

If I am directly installing a local .gem using traveling-ruby gem
as `path/to/bin/gem install ph_latex'
ph_latex gem file is there in the same path.
It throws error:

ERROR:  Error installing ph_latex:
	ERROR: Failed to build gem native extension.

    /Users/mukarram/mysites/temp/traveling-ruby-native-extensions-demo-master/packaging/traveling-ruby-20150517-2.2.2-osx/bin/ruby -r ./siteconf20171003-40173-1ewewro.rb extconf.rb
mkmf.rb can't find header files for ruby at /Users/mukarram/mysites/temp/traveling-ruby-native-extensions-demo-master/packaging/traveling-ruby-20150517-2.2.2-osx/lib/ruby/include/ruby.h

extconf failed, exit code 1

Gem files will remain installed in /Users/mukarram/mysites/temp/traveling-ruby-native-extensions-demo-master/packaging/traveling-ruby-20150517-2.2.2-osx/lib/ruby/gems/2.2.0/gems/nokogiri-1.8.1 for inspection.
Results logged to /Users/mukarram/mysites/temp/traveling-ruby-native-extensions-demo-master/packaging/traveling-ruby-20150517-2.2.2-osx/lib/ruby/gems/2.2.0/extensions/x86_64-darwin-13/2.2.0-static/nokogiri-1.8.1/gem_make.out```

[FloorD]

We're combining issues into larger milestones. Thank you for reporting this issue.