Could it be DropBox syncing? If you have that folder set to automatically synchronize with anything, make sure you exclude the entire .pio folder and all of its subfolders from your synchronization. PlatformIO expects to have full control of that folder and will be very, very unhappy if other processes try to lock onto those files. Every time you build/compile your program there are a bunch of new files created and others modified or deleted in sub-directories of that .pio file. Those files are not useful to archive, but are needed to successfully convert your code from what you see into assembly that your board can use.
You have git installed, right? I don’t think you’d even get this far without it. I think either VSCode or Atom (both) include it.
Otherwise, try running the same install command a few times. As long as it gets a little farther each time, it’s fine. I think this crashing happens when the background processes for the linter and compiler are trying to read your libraries while you’re installing them in the foreground.