installed libgtk-3-0_3.22.11-1_amd64.deb and now I get black screen after boot

[stupid-genius]

Your system information

• Steam client version: can't boot into steam
• SteamOS version: can't boot into steam
• Opted into Steam client beta?: yes
• Opted into SteamOS beta?: don't know what this is
• Have you checked for updates in Settings > System?: can't boot into steam

Please describe your issue in as much detail as possible:

I manually installed a library package and broke my system; I get the infamous black screen after boot.

$ dpkg -i libgtk-3-0_3.22.11-1_amd64.deb
$ apt-get -f install

I can get into a TTY, but I can't figure out exactly what's broken. I've been trying to figure out how to "rollback" from those two commands, but deciphering the logs is difficult.

in /var/log/dpkg.log.1 I see: 2020-04-18 19:37:14 upgrade libgtk-3-0:amd64 3.14.5-1+deb8u1+bsos1 3.22.11-1 but then later in that log, I see: 2020-04-18 19:37:49 remove libgtk-3-0:amd64 3.22.11-1 <none> I'm not at all familiar with the inner workings of dpkg or apt, but that seems unexpected to me.

less /var/log/apt/history.log.1.gz shows:

Start-Date: 2020-04-18  19:13:33
Commandline: apt-get install -f
Install: xdg-utils:amd64 (1.1.0~rc1+git20111210-7.4+deb8u1+bsos1, automatic), libpango1.0-0:amd64 (1.36.8-3+bsos2, automatic)
Remove: minecraft-launcher:amd64 (2.1.13829)
End-Date: 2020-04-18  19:13:34

Start-Date: 2020-04-18  19:37:37
Commandline: apt-get -f install
Remove: zenity:amd64 (3.14.0-1+bsos2), gir1.2-clutter-1.0:amd64 (1.20.0-1+bsos2), libclutter-gtk-1.0-0:amd64 (1.6.0-1+bsos2), gnome-shell:amd64 (3.14.4-1~deb8u1+bsos1), empathy:amd64 (3.12.7-1+bsos2), gir1.2-evince-3.0:amd64 (3.14.1-2+deb8u2+bsos1), libchamplain-gtk-0.12-0:amd64 (0.12.9-1+bsos2), gnome-online-accounts:amd64 (3.14.2-1+bsos2), mousetweaks:amd64 (3.12.0-1+bsos2), caribou:amd64 (0.4.15-1+bsos2), libgail-3-0:amd64 (3.14.5-1+deb8u1+bsos1), gnome-packagekit:amd64 (3.14.0-1+steamos1+bsos2), libvte-2.91-0:amd64 (0.38.1-2+bsos2), libnm-gtk0:amd64 (0.9.10.0-2+bsos2), evince:amd64 (3.14.1-2+deb8u2+bsos1), gnome-session-bin:amd64 (3.14.0-2+steamos1+bsos1), libcheese7:amd64 (3.14.1-2+bsos2), libcolord-gtk1:amd64 (0.1.25-1.1+bsos2), tracker-gui:amd64 (1.2.4-2+bsos2), gir1.2-gnomedesktop-3.0:amd64 (3.14.1-1+bsos2), gnome-terminal:amd64 (3.14.1-1+deb8u1+bsos1), gnome-shell-extensions:amd64 (3.14.2-1+bsos1), gnome-system-monitor:amd64 (3.14.1-1+bsos2), libnautilus-extension1a:amd64 (3.14.1-2+bsos2), gdm3:amd64 (3.14.1-7+deb8u1+bsos1), eog:amd64 (3.14.1-1+bsos2), gir1.2-gtkclutter-1.0:amd64 (1.6.0-1+bsos2), gnome-disk-utility:amd64 (3.12.1-1+bsos2), steam-launcher:amd64 (1.0.0.61), lightdm-gtk-greeter:amd64 (1.8.5-2+bsos2), gir1.2-gtk-3.0:amd64 (3.14.5-1+deb8u1+bsos1), gir1.2-peas-1.0:amd64 (1.12.1-2+bsos2), gir1.2-gkbd-3.0:amd64 (3.6.0-1+bsos2), gstreamer1.0-clutter:amd64 (2.0.12-1+bsos2), gnome-calculator:amd64 (3.14.1-1+bsos2), gnome-session:amd64 (3.14.0-2+steamos1+bsos1), gnome-icon-theme-symbolic:amd64 (3.12.0-1+bsos3), libgdict-1.0-6:amd64 (3.14.1-1+bsos2), libwnck-3-0:amd64 (3.4.9-3+bsos2), libgnome-desktop-3-10:amd64 (3.14.1-1+bsos2), gnome-packagekit-session:amd64 (3.14.0-1+steamos1+bsos2), libgnomekbd8:amd64 (3.6.0-1+bsos2), libgjs0e:amd64 (1.42.0-1+bsos2), gnome-themes-standard-data:amd64 (3.14.2.2-1+bsos2), gucharmap:amd64 (3.14.1-1+bsos2), libgoa-backend-1.0-1:amd64 (3.14.2-1+bsos2), libgweather-3-6:amd64 (3.14.1-1+bsos2), gnome-control-center:amd64 (3.14.2-3+steamos1+bsos1), libcaribou0:amd64 (0.4.15-1+bsos2), libgtk-3-bin:amd64 (3.14.5-1+deb8u1+bsos1), gnome-core:amd64 (3.14+3+steamosb1+bsos1), libfolks-eds25:amd64 (0.10.0-1+bsos2), iceweasel:amd64 (60.7.0esr-1~deb8u1+bsos3), gir1.2-clutter-gst-2.0:amd64 (2.0.12-1+bsos2), libgnome-bluetooth13:amd64 (3.14.0-2+bsos2), libcaribou-gtk3-module:amd64 (0.4.15-1+bsos2), gir1.2-gcr-3:amd64 (3.14.0-2+bsos2), network-manager-gnome:amd64 (0.9.10.0-2+bsos2), gnome-contacts:amd64 (3.14.1-1+bsos2), libclutter-1.0-0:amd64 (1.20.0-1+bsos2), baobab:amd64 (3.14.1-1+bsos2), gir1.2-nmgtk-1.0:amd64 (0.9.10.0-2+bsos2), vino:amd64 (3.14.0-2+bsos2), libtotem0:amd64 (3.14.0-2+bsos1), totem:amd64 (3.14.0-2+bsos1), gir1.2-caribou-1.0:amd64 (0.4.15-1+bsos2), libgtksourceview-3.0-1:amd64 (3.14.1-1+bsos2), gir1.2-mutter-3.0:amd64 (3.14.4-1~deb8u1+bsos1), minecraft-launcher:amd64 (2.1.13829), gnome-dictionary:amd64 (3.14.1-1+bsos2), gnome-user-guide:amd64 (3.14.1-1+bsos3), gnome-keyring:amd64 (3.14.0-1+bsos2), nautilus:amd64 (3.14.1-2+bsos2), dconf-editor:amd64 (0.22.0-1+bsos2), libgtkmm-3.0-1:amd64 (3.14.0-1+bsos2), libwebkitgtk-3.0-0:amd64 (2.4.9-1~deb8u1+bsos1), gcr:amd64 (3.14.0-2+bsos2), gir1.2-gtksource-3.0:amd64 (3.14.1-1+bsos2), caribou-antler:amd64 (0.4.15-1+bsos2), libyelp0:amd64 (3.14.1-1+bsos2), libevview3-3:amd64 (3.14.1-2+deb8u2+bsos1), libcanberra-gtk3-0:amd64 (0.30-2.1+bsos2), libgtk-3-0:amd64 (3.22.11-1), firefox-esr:amd64 (60.7.0esr-1~deb8u1+bsos3), steam:i386 (1.0.0.61), libcheese-gtk23:amd64 (3.14.1-2+bsos2), gvfs-backends:amd64 (1.22.2-1+steamos1+bsos1), adwaita-icon-theme:amd64 (3.14.0-2+bsos2), gnome-sushi:amd64 (3.12.0-2+bsos2), gnome-settings-daemon:amd64 (3.14.2-3+deb8u1+bsos1), gnome-screenshot:amd64 (3.14.0-1+deb8u1+bsos1), gkbd-capplet:amd64 (3.6.0-1+bsos2), gnome-font-viewer:amd64 (3.14.0-2+bsos2), gjs:amd64 (1.42.0-1+bsos2), mutter:amd64 (3.14.4-1~deb8u1+bsos1), gedit:amd64 (3.14.0-3+bsos2), lightdm:amd64 (1.10.3-3+steamos2+bsos1), libclutter-gst-2.0-0:amd64 (2.0.12-1+bsos2), evolution-data-server:amd64 (3.12.9~git20141128.5242b0-2+deb8u4+bsos1), libgtk-3-common:amd64 (3.14.5-1+deb8u1+bsos1), metacity:amd64 (3.14.3-1+bsos2), policykit-1-gnome:amd64 (0.105-2+bsos2), gnome-icon-theme:amd64 (3.12.0-1+bsos3), libmetacity-private2:amd64 (3.14.3-1+bsos2), gnome-bluetooth:amd64 (3.14.0-2+bsos2), libpeas-1.0-0:amd64 (1.12.1-2+bsos2), libgucharmap-2-90-7:amd64 (3.14.1-1+bsos2), libchamplain-0.12-0:amd64 (0.12.9-1+bsos2), gir1.2-gnomebluetooth-1.0:amd64 (3.14.0-2+bsos2), libevdocument3-4:amd64 (3.14.1-2+deb8u2+bsos1), dconf-tools:amd64 (0.22.0-1+bsos2), yelp:amd64 (3.14.1-1+bsos2), gnome-system-log:amd64 (3.9.90-2+bsos2), gnome-themes-standard:amd64 (3.14.2.2-1+bsos2), gir1.2-webkit-3.0:amd64 (2.4.9-1~deb8u1+bsos1), gnome-user-share:amd64 (3.14.0-2+bsos2), libmutter0e:amd64 (3.14.4-1~deb8u1+bsos1), libgcr-ui-3-1:amd64 (3.14.0-2+bsos2)
End-Date: 2020-04-18  19:37:52

I was hoping the fix would be as simple as reinstalling the original package 3.14.5-1+deb8u1+bsos1, but that did not help.

root@steamos:~# apt-cache policy libgtk-3-0
libgtk-3-0:
  Installed: 3.14.5-1+deb8u1+bsos1
  Candidate: 3.14.5-1+deb8u1+bsos1

I broke my system; does anyone know how to fix it?