Merge rubygems master.

  This is RC version of Rubygems 2.7.0.
  https://github.com/rubygems/rubygems/commit/688fb7e83c13c3fe7c2bb03c49a2db4c82852aee

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60133 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 20 insertions, 3 deletions

diff --git a/lib/rubygems/request_set.rb b/lib/rubygems/request_set.rb
index 5541e64b88..95a8eed1af 100644
--- a/lib/rubygems/request_set.rb
+++ b/lib/rubygems/request_set.rb
@@ -163,9 +163,26 @@ class Gem::RequestSet
         end
       end
 
-      spec = req.spec.install options do |installer|
-        yield req, installer if block_given?
-      end
+      spec =
+        begin
+          req.spec.install options do |installer|
+            yield req, installer if block_given?
+          end
+        rescue Gem::RuntimeRequirementNotMetError => e
+          recent_match = req.spec.set.find_all(req.request).sort_by(&:version).reverse_each.find do |s|
+            s = s.spec
+            s.required_ruby_version.satisfied_by?(Gem.ruby_version) && s.required_rubygems_version.satisfied_by?(Gem.rubygems_version)
+          end
+          if recent_match
+            suggestion = "The last version of #{req.request} to support your Ruby & RubyGems was #{recent_match.version}. Try installing it with `gem install #{recent_match.name} -v #{recent_match.version}`"
+            suggestion += " and then running the current command again" unless @always_install.include?(req.spec.spec)
+          else
+            suggestion = "There are no versions of #{req.request} compatible with your Ruby & RubyGems"
+            suggestion += ". Maybe try installing an older version of the gem you're looking for?" unless @always_install.include?(req.spec.spec)
+          end
+          e.suggestion = suggestion
+          raise
+        end
 
       requests << spec
     end