There's a problem with trying to install wine 5.0 on Ubuntu 18.04. There's a missing faudio dependency not present in the Ubuntu 18.04 repositories that fouls up the entire process. The instructions on the WineHQ site aren't as clear as they should be, and in typical Linux "community" fashion, they have no intention of updating them to be more clear (Why make someone else's life easier when you can watch them struggle? AMIRITE!?)
Fear not dear reader. I've run into this same problem myself, so hopefully this guide will help you out. Here's what you need to do to get Wine 5.0 installed on Ubuntu 18.04. I ran into this problem trying to install Lutris by following their instructions here. I found the following fix here, so thanks to the original author for the insight into fixing this problem.
Add 32-bit support:
sudo dpkg --add-architecture i386
Download the WineHQ repository key:
wget -nc https://dl.winehq.org/wine-builds/winehq.key -O /tmp/winehq.key
Install the WinHQ repository key:
sudo apt-key add /tmp/winehq.key
Install the Wine Repository:
sudo apt-add-repository 'deb https://dl.winehq.org/wine-builds/ubuntu/ bionic main'
Download the key needed for the OBS faudio repository:
wget -nv https://download.opensuse.org/repositories/Emulators:/Wine:/Debian/xUbuntu_18.04/Release.key -O /tmp/Release.key
Install the key:
sudo apt-key add - < /tmp/Release.key
Add the OBS faudio repository:
sudo apt-add-repository 'deb https://download.opensuse.org/repositories/Emulators:/Wine:/Debian/xUbuntu_18.04/ ./'
Update your repositories:
sudo apt-get update
sudo apt install --install-recommends winehq-stable
And you're done!