Ignore spec different platfroms

bundler/lib/bundler/stub_specification.rb

@@ -38,7 +38,11 @@ def ignored?
       @ignored = missing_extensions?
       return false unless @ignored
 
-      warn "Source #{source} is ignoring #{self} because it is missing extensions"
+      # If we share GEM_HOME for all of Ruby platform, the platform specific gem always warn that specification.
+      # ex `jruby-launcher` and CRuby
+      if (platform == Gem::Platform::RUBY || Gem::Platform.local === platform) && RUBY_ENGINE != "jruby"
+        warn "Source #{source} is ignoring #{self} because it is missing extensions"
+      end
 
       true
     end

bundler/spec/bundler/stub_specification_spec.rb

@@ -12,6 +12,17 @@
     described_class.from_stub(gemspec)
   end
 
+  let(:with_java_gem_stub_spec) do
+    gemspec = Gem::Specification.new do |s|
+      s.name = "gemname"
+      s.version = "1.0.0"
+      s.loaded_from = __FILE__
+      s.platform = "java"
+    end
+
+    described_class.from_stub(gemspec)
+  end
+
   describe "#from_stub" do
     it "returns the same stub if already a Bundler::StubSpecification" do
       stub = described_class.from_stub(with_bundler_stub_spec)
@@ -43,6 +54,17 @@
     end
   end
 
+  describe "#ignored?" do
+    skip "This example is only for without JRuby" if RUBY_ENGINE == "jruby"
+
+    it "returns true if the gem is for different platform" do
+      stub = described_class.from_stub(with_java_gem_stub_spec)
+      allow(stub).to receive(:missing_extensions?).and_return(true)
+      expect(stub).to_not receive(:warn)
+      expect(stub.ignored?).to be true
+    end
+  end
+
   describe "#missing_extensions?" do
     it "returns false if manually_installed?" do
       stub = described_class.from_stub(with_bundler_stub_spec)

lib/rubygems/basic_specification.rb

@@ -73,8 +73,12 @@ def base_dir
   def contains_requirable_file?(file)
     if ignored?
       if platform == Gem::Platform::RUBY || Gem::Platform.local === platform
-        warn "Ignoring #{full_name} because its extensions are not built. " \
-             "Try: gem pristine #{name} --version #{version}"
+        # RubyGems warns gem specification of C extensions. But JRuby couldn't
+        # rebuild with `gem pristine` command. So, we skip the warning.
+        if RUBY_ENGINE != "jruby"
+          warn "Ignoring #{full_name} because its extensions are not built. " \
+              "Try: gem pristine #{name} --version #{version}"
+        end
       end
 
       return false

test/rubygems/test_gem.rb

@@ -1308,8 +1308,12 @@ def test_self_try_activate_missing_extensions
       refute Gem.try_activate "nonexistent"
     end
 
-    expected = "Ignoring ext-1 because its extensions are not built. " \
+    expected = if RUBY_ENGINE == "jruby"
+      ""
+    else
+      "Ignoring ext-1 because its extensions are not built. " \
                "Try: gem pristine ext --version 1\n"
+    end
 
     assert_equal expected, err
   end

test/rubygems/test_gem_specification.rb

@@ -1557,8 +1557,12 @@ def test_contains_requirable_file_eh_extension
       refute @ext.contains_requirable_file? "nonexistent"
     end
 
-    expected = "Ignoring ext-1 because its extensions are not built. " \
+    expected = if RUBY_ENGINE == "jruby"
+      ""
+    else
+      "Ignoring ext-1 because its extensions are not built. " \
                "Try: gem pristine ext --version 1\n"
+    end
 
     assert_equal expected, err
   end

test/rubygems/test_gem_stub_specification.rb

@@ -71,8 +71,12 @@ def test_contains_requirable_file_eh_extension
         refute stub.contains_requirable_file? "nonexistent"
       end
 
-      expected = "Ignoring stub_e-2 because its extensions are not built. " \
+      expected = if RUBY_ENGINE == "jruby"
+        ""
+      else
+        "Ignoring stub_e-2 because its extensions are not built. " \
                  "Try: gem pristine stub_e --version 2\n"
+      end
 
       assert_equal expected, err
     end