test-bundled-gems: select bundled gems to test by BUNDLED_GEMS

common.mk

@@ -1363,8 +1363,9 @@ no-test-bundled-gems:
 # Override this to allow failure of specific gems on CI
 # TEST_BUNDLED_GEMS_ALLOW_FAILURES =
 
+BUNDLED_GEMS =
 test-bundled-gems-run: $(PREPARE_BUNDLED_GEMS)
-	$(Q) $(XRUBY) $(tooldir)/test-bundled-gems.rb
+	$(Q) $(XRUBY) $(tooldir)/test-bundled-gems.rb $(BUNDLED_GEMS)
 
 test-bundler-precheck: $(TEST_RUNNABLE)-test-bundler-precheck
 no-test-bundler-precheck:

tool/test-bundled-gems.rb

@@ -11,6 +11,7 @@ ruby = ENV['RUBY'] || RbConfig.ruby
 File.foreach("#{gem_dir}/bundled_gems") do |line|
   next if /^\s*(?:#|$)/ =~ line
   gem = line.split.first
+  next if ARGV.any? {|pat| !File.fnmatch?(pat, gem)}
   puts "\nTesting the #{gem} gem"
 
   test_command = "#{ruby} -C #{gem_dir}/src/#{gem} -Ilib #{rake} test"