code: function chownErOk (er) {
      if (!er)
        return true
  
      if (er.code === "ENOSYS")
        return true
  
      var nonroot = !process.getuid || process.getuid() !== 0
      if (nonroot) {
        if (er.code === "EINVAL" || er.code === "EPERM")
          return true
      }
  
      return false
    }
docs: ENOSYS means that the fs doesn't support the op. Just ignore that, because it doesn't matter.  if there's no getuid, or if getuid() is something other than 0, and the error is EINVAL or EPERM, then just ignore it.  This specific case is a silent failure in cp, install, tar, and most other unix tools that manage permissions.  When running as root, or if other types of errors are encountered, then it's strict.