apt supports installing packages via e.g. “apt install ./keyring.deb”. Not
everybody knows this¹, and in fact it turns out to not be documented in the
manpage.
Apparently, the feature was originally introduced in commit
0d29b9d4368284782862c7b507c47002b79ddb27 by Michael Vogt, calling the feature
“local deb install”.
Later, commit 5465192b9aeb1ccea778950ccf2d1b7b32f2cd91 by David Kalnischkies
refines the feature and calls it “volatile sources”.
Neither commit updates the manpages, and I can’t see a corresponding prose
paragraph or hint in the synopsis in the apt(8) manpage.
Could you update the manpage to include this feature please?
① https://github.com/i3/i3.github.io/pull/35