System.IO.IOException : The process cannot access the file 'index' because it is being used by another process.
Stack Trace:
at System.IO.Directory.DeleteHelper(String fullPath, String userPath, Boolean recursive, Boolean throwOnTopLevelDirectoryNotFound, WIN32_FIND_DATA& data)
at System.IO.Directory.Delete(String fullPath, String userPath, Boolean recursive, Boolean checkHost)
at Libplanet.Tests.Store.FileStoreFixture.Dispose()
at Libplanet.Tests.Net.SwarmTest.Dispose()
at ReflectionAbstractionExtensions.DisposeTestClass(ITest test, Object testClass, IMessageBus messageBus, ExecutionTimer timer, CancellationTokenSource cancellationTokenSource)
See also https://travis-ci.com/dahlia/libplanet/jobs/187118894#L2315-L2322.