Thanks @tmigone and @dtischler. I will address each issue in a separate post.
Here’s what I mean by “stopped working”:
$ balena push <app-name>
[Info] Starting build for <app-name>, user <user-name>
[Info] Dashboard link: https://dashboard.balena-cloud.com/apps/.../devices
[Info] Building on arm02
[Info] Pulling previous images for caching purposes...
[Success] Successfully pulled cache images
[main] Step 1/18 : FROM balenablocks/audio:raspberrypi3
[main] ---> e6c00128d96d
[main] Step 2/18 : RUN install_packages xserver-xorg-core xinit lxsession desktop-file-utils raspberrypi-ui-mods rpd-icons gtk2-engines-clearlookspix matchbox-keyboard python3 python3-pip python3-picamera iceweasel xterm
[main] ---> Running in df6f55cf9876
[main] fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/main/armv7/APKINDEX.tar.gz
[main] fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/community/armv7/APKINDEX.tar.gz
[main] ERROR: unable to select packages:
[main]
[main] gtk2-engines-clearlookspix (no such package):
[main] required by: world[gtk2-engines-clearlookspix]
...
[main] The command '/bin/sh -c install_packages xserver-xorg-core xinit lxsession desktop-file-utils raspberrypi-ui-mods rpd-icons gtk2-engines-clearlookspix matchbox-keyboard python3 python3-pip python3-picamera iceweasel xterm' returned a non-zero code: 7
[Info] Uploading images
[Success] Successfully uploaded images
[Error] Some services failed to build:
[Error] Service: main
[Error] Error: The command '/bin/sh -c install_packages xserver-xorg-core xinit lxsession desktop-file-utils raspberrypi-ui-mods rpd-icons gtk2-engines-clearlookspix matchbox-keyboard python3 python3-pip python3-picamera iceweasel xterm' returned a non-zero code: 7
[Info] Built on arm02
[Error] Not deploying release.
Remote build failed
That is an issue with the move of Balena Blocks from Buster to Alpine.
Yes, I am able to pin to a specific release and make a functional version work. I still see the errors above, but I can move a new device to a specific release of the application.