Comment 1 for bug 1646649

Here's the Traceback:

Traceback (most recent call last):
  File "/usr/lib/update-notifier/package-data-downloader", line 327, in <module>
    process_download_requests()
  File "/usr/lib/update-notifier/package-data-downloader", line 229, in process_download_requests
    for para in hook.iter_paragraphs(open(file)):
FileNotFoundError: [Errno 2] No such file or directory: '/usr/share/package-data-downloads/ttf-mscorefonts-installer'

It's quite odd given that we find file using os.listdir() shortly before trying to open it.