multithreaded file source breaks interpretation #1035
Description
Described here: scikit-hep/coffea#930.
At first this was treated as an fsspec issue introduced at some point during the integration. However I found out it's not fsspec related and it's reproducible by other multithreaded sources such as uproot.source.file.MultithreadedFileSource (when using more than one thread). I guess this is a race condition and it's more likely to happen with fsspec since it launches all requests at once.