So, fungalnet gave you the answer, your obarun-testing field do not contain the Server part
well, in your /etc/pacman.conf ...
# [obarun-testing]
# SigLevel = Required
# Server = https://repo.obarun.org/$arch/testing
[obarun]
SigLevel = Required
Server = https://repo.obarun.org/$arch
using testing repo or not , it's up to you.
s6-rc-init: fatal: invalid database size in /home/mdc/service/enabled/rc/compiled/current
please give me the output of
$ readlink /home/mdc/service/enabled/rc/compiled/current
your service database seems corrupted in some part, you should rebuild your service database pointed by /home/mdc/service/enabled/rc/compiled/current