apt shows downloads from -proposed pocket when it should use -updates pocket

[Seth Arnold]

I wanted to test an SRU kernel in -proposed; as suggested by the Wiki page, I used the following apt preferences to pin the trusty-proposed pocket to a lower priority:

$ cat /etc/apt/preferences.d/proposed-updates
Package: *
Pin: release a=trusty-proposed
Pin-Priority: 400

After installing the kernel package, I started a normal update.

apt-get -us dist-upgrade didn't show any updates coming via proposed, but the actual apt-get -u dist-upgrade claimed the packages were coming from trusty-proposed all the same:

sarnold@hunt:/var/cache/apt$ sudo apt-get -us dist-upgrade | grep prop
sarnold@hunt:/var/cache/apt$ sudo apt-get -u dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:
  linux-headers-3.13.0-66 linux-headers-3.13.0-66-generic
  linux-image-3.13.0-66-generic linux-image-extra-3.13.0-66-generic
  linux-tools-3.13.0-66 linux-tools-3.13.0-66-generic
Use 'apt-get autoremove' to remove them.
The following NEW packages will be installed:
  linux-headers-3.13.0-68 linux-headers-3.13.0-68-generic
  linux-image-3.13.0-68-generic linux-image-extra-3.13.0-68-generic
  linux-tools-3.13.0-68 linux-tools-3.13.0-68-generic squashfs-tools
The following packages will be upgraded:
  apport apport-gtk click-reviewers-tools debootstrap firefox
  firefox-locale-en flashplugin-installer fonts-opensymbol grub-common grub-pc
  grub-pc-bin grub2-common krb5-locales libgssapi-krb5-2 libido3-0.1-0
  libk5crypto3 libkrb5-3 libkrb5support0 libnautilus-extension1a
  libreoffice-avmedia-backend-gstreamer libreoffice-base-core libreoffice-calc
  libreoffice-common libreoffice-core libreoffice-draw libreoffice-gnome
  libreoffice-gtk libreoffice-impress libreoffice-math libreoffice-ogltrans
  libreoffice-pdfimport libreoffice-presentation-minimizer
  libreoffice-style-human libreoffice-style-tango libreoffice-writer
  libxen-4.4 libxenstore3.0 libxml2 libxml2-dev libxml2-utils linux-firmware
  linux-generic linux-headers-generic linux-image-generic linux-libc-dev
  linux-tools-common linux-tools-generic nautilus nautilus-data
  notify-osd-icons python-apport python-libxml2 python-problem-report
  python3-apport python3-problem-report python3-uno unity-settings-daemon
  uno-libs3 unzip ure wpasupplicant
61 upgraded, 7 newly installed, 0 to remove and 0 not upgraded.
Need to get 167 MB/213 MB of archives.
After this operation, 276 MB of additional disk space will be used.
Do you want to continue? [Y/n]
Err http://mirror.pnl.gov/ubuntu/ trusty-updates/main libxml2 amd64 2.9.1+dfsg1-3ubuntu4.5
  403 Forbidden
Get:1 http://security.ubuntu.com/ubuntu/ trusty-security/main libxml2 amd64 2.9.1+dfsg1-3ubuntu4.5 [571 kB]
Err http://mirror.pnl.gov/ubuntu/ trusty-updates/main grub-common amd64 2.02~beta2-9ubuntu1.4
  403 Forbidden
Get:2 http://archive.ubuntu.com/ubuntu/ trusty-proposed/main grub-common amd64 2.02~beta2-9ubuntu1.4 [1,676 kB]
Err http://mirror.pnl.gov/ubuntu/ trusty/main squashfs-tools amd64 1:4.2+20130409-2
  403 Forbidden
Get:3 http://security.ubuntu.com/ubuntu/ trusty-security/main libreoffice-calc amd64 1:4.2.8-0ubuntu3 [5,940 kB]
Get:4 http://archive.ubuntu.com/ubuntu/ trusty-proposed/main python3-problem-report all 2.14.1-0ubuntu3.19 [9,748 B]
Get:5 http://archive.ubuntu.com/ubuntu/ trusty-proposed/main python3-apport all 2.14.1-0ubuntu3.19 [75.3 kB]
Get:6 http://archive.ubuntu.com/ubuntu/ trusty-proposed/main apport all 2.14.1-0ubuntu3.19 [182 kB]
Get:7 http://archive.ubuntu.com/ubuntu/ trusty-proposed/main apport-gtk all 2.14.1-0ubuntu3.19 [9,558 B]
Get:8 http://archive.ubuntu.com/ubuntu/ trusty-proposed/main libnautilus-extension1a amd64 1:3.10.1-0ubuntu9.11 [52.1 kB]
Get:9 http://archive.ubuntu.com/ubuntu/ trusty-proposed/main linux-firmware all 1.127.18 [24.4 MB]
Get:10 http://security.ubuntu.com/ubuntu/ trusty-security/main libreoffice-gnome amd64 1:4.2.8-0ubuntu3 [90.2 kB]
Get:11 http://security.ubuntu.com/ubuntu/ trusty-security/main libreoffice-gtk amd64 1:4.2.8-0ubuntu3 [222 kB]
Get:12 http://security.ubuntu.com/ubuntu/ trusty-security/main libreoffice-impress amd64 1:4.2.8-0ubuntu3 [1,208 kB]
Get:13 http://security.ubuntu.com/ubuntu/ trusty-security/main libreoffice-writer amd64 1:4.2.8-0ubuntu3 [9,452 kB]
10% [9 linux-firmware 5,524 kB/24.4 MB 23%] [13 libreoffice-writer 682 kB/9,452^C

Spot-checking the packages shows that this is entirely cosmetic:
sarnold@hunt:/var/cache/apt$ apt-cache policy linux-firmware
linux-firmware:
  Installed: 1.127.16
  Candidate: 1.127.18
  Version table:
     1.127.18 0
        500 http://mirror.pnl.gov/ubuntu/ trusty-updates/main amd64 Packages
        400 http://archive.ubuntu.com/ubuntu/ trusty-proposed/main amd64 Packages
 *** 1.127.16 0
        500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
        100 /var/lib/dpkg/status
     1.127 0
        500 http://mirror.pnl.gov/ubuntu/ trusty/main amd64 Packages
sarnold@hunt:/var/cache/apt$ apt-cache policy python3-apport
python3-apport:
  Installed: 2.14.1-0ubuntu3.18
  Candidate: 2.14.1-0ubuntu3.19
  Version table:
     2.14.1-0ubuntu3.19 0
        500 http://mirror.pnl.gov/ubuntu/ trusty-updates/main amd64 Packages
        400 http://archive.ubuntu.com/ubuntu/ trusty-proposed/main amd64 Packages
 *** 2.14.1-0ubuntu3.18 0
        500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
        100 /var/lib/dpkg/status
     2.14.1-0ubuntu3 0
        500 http://mirror.pnl.gov/ubuntu/ trusty/main amd64 Packages
sarnold@hunt:/var/cache/apt$

But it is certainly enough to make me ^C the download and inspect what's going on.

Thanks

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: apt 1.0.1ubuntu2.10
ProcVersionSignature: Ubuntu 3.13.0-67.110-generic 3.13.11-ckt27
Uname: Linux 3.13.0-67-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.18
Architecture: amd64
CurrentDesktop: Unity
Date: Mon Nov 16 18:22:13 2015
InstallationDate: Installed on 2012-10-18 (1124 days ago)
InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120823.1)
SourcePackage: apt
UpgradeStatus: Upgraded to trusty on 2014-04-12 (584 days ago)

[Adam Conrad (adconrad)]

apt selects which mirror/repo to download from based on their position in sources.list. If two mirrors contain the identical file, the first one will be picked, even if it's not actually the one that would win according to apt-cache policy. This is by design (based on the idea that you'll place closer/faster mirrors first), but I can see how it's disconcerting in this case.

(We take advantage of this same feature in our default sources.list by always placing -updates before security, so people only fall back to the security mirror if their local updates is lagging behind).

[Julian Andres Klode (juliank)]

As Adam wrote, that is documented and by design: The order of sources determines the source for a given package version.