make installkernel: failure: install: /usr/lib/debug/boot/kernel: No such file or directory

Hello,

Host is actual running 

15.0-CURRENT #40 main-n275030-46a9fb7287f4: Sat Jan 25 07:09:38 CET 2025 amd64

Trying to rebuild (from clean/scratch after "make cleanworld") and install kernel/world.

make kernel works fine. 
make installkernel bails out with:

[...]
===> usb/rsufw/rsurtl8712fw (install)
install -T release -o root -g wheel -m 444   rsu-rtl8712fw.ko /boot/kernel/
===> usb/mtw (install)
install -T release -o root -g wheel -m 444   if_mtw.ko /boot/kernel/
install -T dbg -o root -g wheel -m 444   if_mtw.ko.debug /usr/lib/debug/boot/kernel/
install: /usr/lib/debug/boot/kernel: No such file or directory
*** Error code 71

Stop.
make[5]: stopped making "install" in /usr/src/sys/modules/usb/mtw
*** Error code 1

Stop.
make[4]: stopped making "install" in /usr/src/sys/modules/usb
*** Error code 1

Stop.
make[3]: stopped making "install" in /usr/src/sys/modules
*** Error code 1
[...]

On a similar box running CURRENT this failure doesn't show up, but the (working) box has been
updated more often within the past two weeks.

I fear that I might have issued "make delete-old" on the wrong console prior to "make
installworld", but I do not know wether the failure shown is a typical/well known symptome.

Any tips and tricks to fix this nasty failure?

Thanks in advance

o.h.

-- 

A FreeBSD user