This exception will help diagnose download errors when they occur by printing the specific Exception thrown by the resource downloader. Change-Id: Iab35f85fa305594076bf582228e89dae611ce8df Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/61631 Maintainer: Bobby Bruce <bbruce@ucdavis.edu> Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu> Tested-by: kokoro <noreply+kokoro@google.com>