Please note that this list isn't meant for real-time debugging. If you want real-time help, please join IRC (#s6 on OFTC), that's what it is for.
Apr 10 22:06:53 rpm-builder s6.systemd-boot[15235]: s6-supervise s6-svscan-log: warning: unable to spawn ./run (waiting 60 seconds): No such file or directory
Looks like your scandir isn't empty. Again, do not use s6-svscanboot or anything similar. Start s6-svscan directly. -- Laurent