The recent move of agetty-service into #base-services caused serial
login to stop working here. Previously this worked ...

(agetty-service (agetty-configuration (tty "ttyS1")
							(baud-rate "115200")))

First I tried removing the lines above. Then I tried ...

(define %my-services
  (modify-services %base-services
		   (agetty-service-type config =>
					(agetty-configuration
					 (tty "ttyS1")
					 (baud-rate "115200")))))

I can confirm that ...

root@g1 /home/g1# sudo echo 123 > /dev/ttyS1

... produces "123" on the serial line.

guix (GNU Guix) 0.14.0.2487-58246

config attached (my G54)

TIA - George