Comment 7 for bug 1754356

Can confirm it works.

marco@tricky:/tmp:✓ $ apt-cache policy xdg-user-dirs
xdg-user-dirs:
  Installato: 0.15-2ubuntu6.16.04.1
  Candidato: 0.15-2ubuntu6.16.04.1
  Tabella versione:
 *** 0.15-2ubuntu6.16.04.1 100

Before upgrading:

marco@tricky:/tmp:✓ $ env HOME=/tmp/temp-home xdg-user-dirs-update
marco@tricky:/tmp:✓ $ find /tmp/temp-home/
find: '/tmp/temp-home': No such file or directory

After:

marco@tricky:/tmp:✓ $ env HOME=/tmp/temp-home xdg-user-dirs-update
marco@tricky:/tmp:✓ $ find temp-home/
temp-home/
temp-home/Video
temp-home/Modelli
temp-home/.config
temp-home/.config/user-dirs.locale
temp-home/.config/user-dirs.dirs
temp-home/Documenti
temp-home/Immagini
temp-home/Scaricati
temp-home/Pubblici
temp-home/Scrivania
temp-home/Musica

marco@tricky:/tmp:✓ $ env HOME=/tmp/temp-home xdg-user-dirs-update --set DOWNLOADS \
                     "/tmp/temp-home/sub/folder/of/it/Downloads"
marco@tricky:/tmp:✓ $ cat temp-home/.config/user-dirs.dirs
# This file is written by xdg-user-dirs-update
# If you want to change or add directories, just edit the line you're
# interested in. All local changes will be retained on the next run
# Format is XDG_xxx_DIR="$HOME/yyy", where yyy is a shell-escaped
# homedir-relative path, or XDG_xxx_DIR="/yyy", where /yyy is an
# absolute path. No other format is supported.
#
XDG_DESKTOP_DIR="$HOME/Scrivania"
XDG_DOWNLOAD_DIR="$HOME/Scaricati"
XDG_TEMPLATES_DIR="$HOME/Modelli"
XDG_PUBLICSHARE_DIR="$HOME/Pubblici"
XDG_DOCUMENTS_DIR="$HOME/Documenti"
XDG_MUSIC_DIR="$HOME/Musica"
XDG_PICTURES_DIR="$HOME/Immagini"
XDG_VIDEOS_DIR="$HOME/Video"
XDG_DOWNLOADS_DIR="$HOME/sub/folder/of/it/Downloads"