1 files changed, 10 insertions, 5 deletions
diff --git a/spec/support/rubygems_ext.rb b/spec/support/rubygems_ext.rb
index 5299a7b447..62e2274fbe 100644
--- a/spec/support/rubygems_ext.rb
+++ b/spec/support/rubygems_ext.rb
@@ -23,7 +23,8 @@ module Spec
       "rake" => "13.0.1",
       "builder" => "~> 3.2",
       # ruby-graphviz is used by the viz tests
-      "ruby-graphviz" => ">= 0.a",
+      # for >= Ruby 2.3
+      "ruby-graphviz" => "1.2.4",
     }
 
     extend self
@@ -105,10 +106,14 @@ module Spec
     end
 
     def install_gems(gems)
-      deps = gems.map {|name, req| "'#{name}:#{req}'" }.join(" ")
-      gem = ENV["GEM_COMMAND"] || "#{Gem.ruby} -S gem --backtrace"
-      cmd = "#{gem} install #{deps} --no-document --conservative"
-      system(cmd) || raise("Installing gems #{deps} for the tests to use failed!")
+      require "rubygems/dependency_installer"
+
+      gems.each do |name, req|
+        dependency = Gem::Dependency.new(name, req)
+        next unless dependency.matching_specs.empty?
+
+        Gem::DependencyInstaller.new(:document => false).install(dependency)
+      end
     end
   end
 end