Support skipping an interpreter by setting RUBY_ALL_DEV_SKIP

Note that this is a developer feature, and MUST NOT be used in any
packages.

Gbp-Dch: full

Author: terceiro

debian/README.Debian

@@ -24,3 +24,13 @@ Specifically:
 To programmatically list all the supported versions, install the `gem2deb`
 package and run `dh_ruby --print-supported`. To determine which is the default
 version, just dereference the /usr/bin/ruby symbolic link.
+
+
+Skipping some Ruby version when building packages
+-------------------------------------------------
+
+To skip building/testing against a specific Ruby version that is listed as
+suppotted, you can set e.g. RUBY_ALL_DEV_SKIP=ruby3.2 and get ruby3.2 ignored.
+
+This is a developer feature, intended for very specific use cases, and MUST NOT
+be used in any Debian packages to skip tests and whatnot.

ruby_debian_dev.rb

@@ -2,7 +2,12 @@ module RubyDebianDev
 
   RUBY_INTERPRETERS = {}
 
+  def self.skip
+    @skip ||= (ENV["RUBY_ALL_DEV_SKIP"] || "").split
+  end
+
   def self.has_support_for(ruby)
+    return if skip.include?(ruby)
     RUBY_INTERPRETERS[ruby] = yield
   end