mayCopyFilePath :: (MonadMask m, Katip m) => FilePath -> FilePath -> m ()
mayCopyFilePath srcPath destPath = retryOnException $ do
  shouldCopy <- liftIO $ shouldCopyFile srcPath destPath
  if shouldCopy
    then do
      logInfo $ "Copying <" <> srcPath <> "> to <" <> destPath <> ">."
      liftIO $ copyFile srcPath destPath
    else do
      logDebug $ "Skipping <" <> srcPath <> "> to <" <> destPath <> ">."
  where
    shouldCopyFile srcPath destPath = do
      destExists <- doesFileExist destPath
      if not destExists
        then pure True
        else do
          srcTime <- getModificationTime srcPath
          destTime <- getModificationTime destPath
          srcSize <- getFileSize srcPath
          destSize <- getFileSize destPath
          pure (srcTime > destTime || (srcSize > 0 && destSize == 0))
    retryOnException f =
      recoverAll (exponentialBackoff 1_000_000 <> limitRetries 5) $ \(RetryStatus iterNum cmDelay _) -> do
        logWarn @Text $ "Retrying: " <> show iterNum <> "; cumulative delay: " <> show cmDelay <> "µs."
        f