Installing kernelstub can fail if installed at the same time as an initramfs update

[Ian Santopietro]

If the kernelstub config file doesn't exist during an update to any package that generates a new kernel or initramfs, the kernelstub trigger will fail during that portion of the upgrade and will cause dpkg to error out. This shouldn't ever be a problem, but it would be good to ensure that even if it does come up, it doesn't break things. Perhaps we should ship a default config file with "quiet splash" since these are the default kernel parameters for 90% of installations.

[Ian Santopietro (isantop)]

Log of problem from apt:

sudo apt upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages will be upgraded:
  chromium-browser chromium-browser-l10n chromium-codecs-ffmpeg-extra
  kernelstub libmozjs-38-0 libnss-myhostname libnss-resolve libpam-systemd
  libsystemd0 libudev1 snapd system76-driver system76-driver-nvidia systemd
  systemd-sysv thermald udev
17 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 76.7 MB of archives.
After this operation, 454 kB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://us.archive.ubuntu.com/ubuntu zesty-updates/main amd64 libsystemd0 amd64 232-21ubuntu3 [211 kB]
Get:2 http://us.archive.ubuntu.com/ubuntu zesty-updates/main amd64 libnss-resolve amd64 232-21ubuntu3 [114 kB]
Get:3 http://us.archive.ubuntu.com/ubuntu zesty-updates/main amd64 libpam-systemd amd64 232-21ubuntu3 [116 kB]
Get:4 http://us.archive.ubuntu.com/ubuntu zesty-updates/main amd64 libnss-myhostname amd64 232-21ubuntu3 [36.8 kB]
Get:5 http://us.archive.ubuntu.com/ubuntu zesty-updates/main amd64 systemd amd64 232-21ubuntu3 [2,362 kB]
Get:6 http://us.archive.ubuntu.com/ubuntu zesty-updates/main amd64 udev amd64 232-21ubuntu3 [1,040 kB]
Get:7 http://us.archive.ubuntu.com/ubuntu zesty-updates/main amd64 libudev1 amd64 232-21ubuntu3 [56.4 kB]
Get:8 http://us.archive.ubuntu.com/ubuntu zesty-updates/main amd64 systemd-sysv amd64 232-21ubuntu3 [13.0 kB]
Get:9 http://ppa.launchpad.net/kernelstub/daily/ubuntu zesty/main amd64 kernelstub all 0.21 [6,906 B]
Get:10 http://ppa.launchpad.net/system76-dev/daily/ubuntu zesty/main amd64 system76-driver all 17.04.2~bzr689~ubuntu17.04.1 [53.6 kB]
Get:11 http://ppa.launchpad.net/system76-dev/daily/ubuntu zesty/main amd64 system76-driver-nvidia all 17.04.2~bzr689~ubuntu17.04.1 [11.6 kB]
Get:12 http://us.archive.ubuntu.com/ubuntu zesty-updates/universe amd64 chromium-browser-l10n all 58.0.3029.81-0ubuntu2.17.04.1350 [3,252 kB]
Get:13 http://us.archive.ubuntu.com/ubuntu zesty-updates/universe amd64 chromium-browser amd64 58.0.3029.81-0ubuntu2.17.04.1350 [59.4 MB]
Get:14 http://us.archive.ubuntu.com/ubuntu zesty-updates/universe amd64 chromium-codecs-ffmpeg-extra amd64 58.0.3029.81-0ubuntu2.17.04.1350 [1,034 kB]
Get:15 http://us.archive.ubuntu.com/ubuntu zesty-updates/universe amd64 libmozjs-38-0 amd64 38.2.1~rc0-0ubuntu6 [2,115 kB]
Get:16 http://us.archive.ubuntu.com/ubuntu zesty-updates/main amd64 snapd amd64 2.24.1+17.04 [6,664 kB]
Get:17 http://us.archive.ubuntu.com/ubuntu zesty-updates/main amd64 thermald amd64 1.5.4-4ubuntu1 [191 kB]
Fetched 76.7 MB in 43s (1,769 kB/s)
(Reading database ... 195115 files and directories currently installed.)
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