Run test-unit test without rake task to avoid yard dependency

common.mk

@@ -1429,7 +1429,7 @@ no-test-bundled-gems-prepare: no-test-bundled-gems-precheck
 yes-test-bundled-gems-prepare: yes-test-bundled-gems-precheck
 	$(ACTIONS_GROUP)
 	$(XRUBY) -C "$(srcdir)" bin/gem install --no-document \
-		--install-dir .bundle --conservative "bundler" "minitest:~> 5" "test-unit" "rake" "hoe" "yard" "packnga" "rexml" "json-schema" "test-unit-rr" "rake-compiler"
+		--install-dir .bundle --conservative "bundler" "minitest:~> 5" "test-unit" "rake" "hoe" "rexml" "json-schema" "test-unit-rr" "rake-compiler"
 	$(ACTIONS_ENDGROUP)
 
 PREPARE_BUNDLED_GEMS = test-bundled-gems-prepare

tool/test-bundled-gems.rb

@@ -43,6 +43,9 @@ File.foreach("#{gem_dir}/bundled_gems") do |line|
     # environment variable.
     load_path = true
 
+  when "test-unit"
+    test_command = "#{ruby} -C #{gem_dir}/src/#{gem} test/run-test.rb"
+
   when /\Anet-/
     toplib = gem.tr("-", "/")