How to install Debian GUI application on Omarchy?

[sedubois]

In Omarchy, how to install a GUI application in .deb format downloaded directly from the app's website? The app is not available under Install > Package or Install > AUR menus and is only available as a native app, not a web app.

I tried (accepting the default options suggested, not editing the .PKGINFO and .INSTALL files):

yay -S debtab
sudo debtap -u
debtap falco-app_4.3.1_amd64.deb
sudo pacman -U falco-app-4.3.1-1-x86_64.pkg.tar.zst

But it gives an error cannot resolve "gtk", a dependency of "falco-app":

sudo pacman -U falco-app-4.3.1-1-x86_64.pkg.tar.zst
loading packages...
resolving dependencies...
warning: cannot resolve "gtk", a dependency of "falco-app"
:: The following package cannot be upgraded due to unresolvable dependencies:
      falco-app

:: Do you want to skip the above package for this upgrade? [y/N] y
looking for conflicting packages...
 there is nothing to do

[jirpok]

Looks like the correct package name is gtk3, gtk4, not gtk, see here.

[sedubois]

Thanks @jirpok! Removing depend = gtk from .PKGINFO fixes it.

Detailed solution:

• Download debian package (.deb) from the provider website
• Install debtap: yay -S debtap
• Refresh debtap database: sudo debtap -u
• Convert package: debtap falco-app_4.4.4_amd64.deb
  • leave Packager name and package license blank when prompted
  • edit the .PKGINFO when prompted and delete the line depend = gtk but keep depend = gtk3
  • save and exit (no need to modify .INSTALL); this creates falco-app-4.4.4-1-x86_64.pkg.tar.zst
• Install package: sudo pacman -U falco-app-4.4.4-1-x86_64.pkg.tar.zst
• falco-app becomes available in the path and when executed, the GUI opens as expected; it is also available through the walker menu (super-space)

As in-app updates do not work, repeat the above procedure to install newer versions.