Rakefile in rbs-2.8.3 vs Rakefile in rbs-2.8.4

@@ -67,10 +67,18 @@
 
 FileList["test/stdlib/**/*_test.rb"].each do |test|
   task test => :compile do
     sh "#{ruby} -Ilib #{bin}/test_runner.rb #{test}"
   end
-  task stdlib_test: test
+end
+
+task :stdlib_test do
+  test_files = FileList["test/stdlib/**/*_test.rb"].reject do |path|
+    path =~ %r{Ractor}
+  end
+  sh "#{ruby} -Ilib #{bin}/test_runner.rb #{test_files.join(' ')}"
+  # TODO: Ractor tests need to be run in a separate process
+  sh "#{ruby} -Ilib #{bin}/test_runner.rb test/stdlib/Ractor_test.rb"
 end
 
 task :rubocop do
   sh "rubocop --parallel"
 end