...
==> Starting build()...
CMake Error at CMakeLists.txt:17 (project):
VERSION "1.0.0.r3.g8578470" format invalid.
-- Configuring incomplete, errors occurred!
==> ERROR: A failure occurred in build().
Aborting...
-> error making: caelestia-shell-git-exit status 4
-> Failed to install the following packages. Manual intervention is required:
caelestia-shell-git - exit status 4
You should probably add a .service file, there was one before and it's the recommended use on systemd distro, there should be one available on the repo somewhere, it should look something like this :
[Unit]
Description=A very segsy desktop shell.
After=graphical-session.target
[Service]
Type=exec
ExecStart=/etc/xdg/quickshell/caelestia/run.fish
Restart=on-failure
Slice=app-graphical.slice
[Install]
WantedBy=graphical-session.target
Also maybe using quickshell instead of quickshell-git would be better, unless the shell uses feature from the unstable release