Fix Debian package installation

[mathieufrh]

apt won't find the package, better use dpkg to install local .deb packages.

[codecov]

Codecov Report

Merging #2826 into master will increase coverage by 0.03%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2826      +/-   ##
==========================================
+ Coverage   86.64%   86.67%   +0.03%     
==========================================
  Files         570      570              
  Lines       38266    38266              
==========================================
+ Hits        33156    33168      +12     
+ Misses       5110     5098      -12

Flag	Coverage Δ
#gcov	75.5% <ø> (+0.1%)	⬆️
#luacov	89.46% <ø> (+0.01%)	⬆️

Impacted Files	Coverage Δ
lib/awful/layout/suit/corner.lua	88.49% <0%> (+3.53%)	⬆️
spawn.c	86.51% <0%> (+3.72%)	⬆️

[Elv13]

apt won't find the package, better use dpkg to install local .deb packages.

As far as I know, newer versions of apt will accept the .deb package from apt. Only very old ones don't support this (like apt-get). If it was in the wrong dir, then that's an issue. I will check if we can add this to the CI to test those packages when submitting patches. Right now I don't think one of the main devs use a Debian based system for development (AFAIK: 1x Gentoo, 1x Fedora and 2x Arch)

[mathieufrh]

Indeed, you can install .deb packages using apt but you'll have to use apt install ./*.deb, apt install *.deb certainly won't work as apt won't understand that you want to install a local file.

[psychon]

Right now I don't think one of the main devs use a Debian based system for development (AFAIK: 1x Gentoo, 1x Fedora and 2x Arch)

I've been using Debian for ages. Assuming you are counting me for Fedora: That was my previous computer at work. New work computer uses this weird operating system from some little company from redmond. You know, the one that doesn't even understand X11...

[Elv13]

you'll have to use apt install ./*.deb,

Indeed, thanks. Can you update the pull request do use that?