Trying to debug acpi.ko - missing db_readline link

[John]

I'm trying to follow the procedures for debugging ACPI, and I've
followed the instructions to create a module with debugging enabled,
but I can't load it - I get the following error message:

link_elf: symbol db_readline undefined
KLD file acpi.ko - could not finalize loading

Anyone able to kick-start me to the next level?
-- 

John Lind
john at starfire.MN.ORG