Quite regularly, I let my Debian Sid/Unstable chroot stay untouch for a while, and when I need to update it there is not enough free space on the disk for apt to do a normal 'apt upgrade'. I normally would resolve the issue by doing 'apt install <somepackages>' to upgrade only some of the packages in one batch, until the amount of packages to download fall below the amount of free space available. Today, I had about 500 packages to upgrade, and after a while I got tired of trying to install chunks of packages manually. I concluded that I did not have the spare hours required to complete the task, and decided to see if I could automate it. I came up with this small script which I call 'apt-in-chunks':
#!/bin/sh
#
# Upgrade packages when the disk is too full to upgrade every
# upgradable package in one lump. Fetching packages to upgrade using
# apt, and then installing using dpkg, to avoid changing the package
# flag for manual/automatic.
set -e
ignore() {
if [ "$1" ]; then
grep -v "$1"
else
cat
fi
}
for p in $(apt list --upgradable | ignore "$@" |cut -d/ -f1 | grep -v '^Listing...'); do
echo "Upgrading $p"
apt clean
apt install --download-only -y $p
for f in /var/cache/apt/archives/*.deb; do
if [ -e "$f" ]; then
dpkg -i /var/cache/apt/archives/*.deb
break
fi
done
done
The script will extract the list of packages to upgrade, try to download the packages needed to upgrade one package, install the downloaded packages using dpkg. The idea is to upgrade packages without changing the APT mark for the package (ie the one recording of the package was manually requested or pulled in as a dependency). To use it, simply run it as root from the command line. If it fail, try 'apt install -f' to clean up the mess and run the script again. This might happen if the new packages conflict with one of the old packages. dpkg is unable to remove, while apt can do this.
It take one option, a package to ignore in the list of packages to upgrade. The option to ignore a package is there to be able to skip the packages that are simply too large to unpack. Today this was 'ghc', but I have run into other large packages causing similar problems earlier (like TeX).
Update 2018-07-08: Thanks to Paul Wise, I am aware of two alternative ways to handle this. The "unattended-upgrades --minimal-upgrade-steps" option will try to calculate upgrade sets for each package to upgrade, and then upgrade them in order, smallest set first. It might be a better option than my above mentioned script. Also, "aptutude upgrade" can upgrade single packages, thus avoiding the need for using "dpkg -i" in the script above.
As usual, if you use Bitcoin and want to show your support of my activities, please send Bitcoin donations to my address 15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.