Arch Linux

Description:
Currently ruby-cairo gem package lists ruby-native-package-installer gem package as 'make' dependency.
According to ruby gems site: https://rubygems.org/gems/cairo, native-package-installer gem is a runtime dependency.
Also, from version 1.17.4, cairo gem has a new runtime dependency: red-colors. This gem does not seem to have a package in Arch Linux.
The result is that rub-cairo gem (and by consequence ruby-gtk3 gem which depends on ruby-cairo) are not usable (exception is raised, see steps to reproduce).


Additional info:
* package version(s): ruby-cairo 1.17.5-1

Steps to reproduce:
1. verify that ruby-cairo and ruby-native-package-installer gems are not installed.
2. install ruby-cairo
3. launch interactive ruby: irb
4. when in the interactive ruby, issue: require 'cairo'
5. the exception is raised: Gem:MissingSpecError

6. To have more information, in the interactive ruby run the following code:
begin
require 'cairo'
rescue LoadError => e
puts e.message
end

The output should be something like:
Could not find 'native-package-installer' (>= 1.0.3) among 51 total gem(s)

7. install ruby-native-package-installer
8. repeat steps 3-6

This time, the output of the step 6 should be something like:
Could not find 'red-colors' (>= 0) among 51 total gem(s)

9. install red-colors using 'gem' (gem install red-colors)
10. repeat steps 3-4

Output of step 4 should be:
=> true

No, errors, cairo gem works.