I think I misunderstood how to use this tool and I made the input and output directory match. It for several minutes before crashing on a HUGE path. I'm guessing it started operating on itself recursively.
-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app\\pre-appx\\app' }
Actually this is happening to me again even with different paths.
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Same thing happened to me, although you could probably consider it PEBKAC – I initially tried to use an output directory that was a child of the input directory. Eventually, I terminated the command, and tried a different output directory, but that of course tried to copy the very deep/recursed initial output directory, which caused me to think the same error was occurring.
I fixed it by using Git Bash to remove the initial output directory (took a while – Powershell and File Explorer weren't up to the task) and starting the command over with a distinct input and output directory.