Comment 39 for bug 1543280

I can confirm the bug, Ubuntu 16.04.

I know that this is a duplicate of bug #1522675 (not related to synaptic but to apt itself as noted before), but I think that we have two different issues here.

The first is:

W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/andale32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied)

This happens as the directory is not owned by _apt:

cat /etc/passwd | grep apt
_apt:x:105:65534::/nonexistent:/bin/false

ls -la /var/lib/update-notifier/package-data-downloads/
total 12
drwxr-xr-x 3 root root 4096 gen 8 17:50 .
drwxr-xr-x 4 root root 4096 gen 8 17:50 ..
drwxr-xr-x 2 root root 4096 gen 8 17:50 partial

The manual workaround that worked for me and do no create a huge security hole is:

chown _apt /var/lib/update-notifier/package-data-downloads/partial/

Hopefully https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=813786 will fix the issue but can't say till it hit mainstream as I'm a standard user with a LTS installation.

Anyway, and this is the seconde issue, ttf-mscorefonts-installer will refuse to work anyway as ttf-mscorefonts-installer_3.4+nmu1ubuntu2_all.deb is somehow broken getting a redirect from Sourceforge:

curl -kis http://downloads.sourceforge.net/corefonts/arial32.exe | grep "^Location: "
Location: http://downloads.sourceforge.net/project/corefonts/the%20fonts/final/arial32.exe

That contains a space that will make the subsequent request:

E: Failed to fetch https://netcologne.dl.sourceforge.net/project/corefonts/the fonts/final/arial32.exe The HTTP server sent an invalid Content-Range header
E: Download Failed

Installing ttf-mscorefonts-installer_3.6_all.deb from Debian fix the issue so it really has to do with some scripting inside the package (postinst?).