apt-extracttemplates(1) prints inappropriate \r characters in unattended-upgrades

[Daniel Richard G.]

This concerns apt-utils 0.8.16~exp5ubuntu13 in Oneiric, but may potentially be an unattended-upgrades bug.

This morning, I received an unattended-updates log message in my work mail. Curiously, Outlook Web Access did not display the log text, but instead gave me a single .bin file to download. This .bin file contained the plain text of the upgrade log, with the exception of the following bit, as seen in less(1):

----8<----
 system-config-printer-gnome system-config-printer-udev tzdata
 tzdata-java ubufox update-manager update-manager-core vinagre
 xul-ext-ubufox
Packages with upgradable origin but kept back:
 software-center

Package installation log:
^MExtracting templates from packages: 54%^MExtracting templates from packages: 100%
Preconfiguring packages ...
(Reading database ... 225967 files and directories currently installed.)
Preparing to replace libcups2 1.5.0-8ubuntu1 (using .../libcups2_1.5.0-8ubuntu3_amd64.deb) ...
---->8----

I've never seen the "Extracting templates from packages" line in an unattended-upgrades mail message before. I suspect apt-extracttemplates(1) may be thinking it's writing output to a terminal, and not a regular file.

[Daniel Richard G. (skunk)]

Happened again this morning. My Web-mail client gave me the same empty message with a single attachment containing the upgrade log; I've attached the file here.

The common thread seems to be that this only occurs with large upgrades---smaller upgrades don't take as much time to extract templates from the packages, so they don't print the percent-progress indicator with \r characters.