Building stable/13 on recent stable/12 fails

[Johannes Totz]

Hi there,

I'm trying to build stable/13 on a recent stable/12 machine.
But it fails with an error in:
make[4]: 
"/scratch/20220306_001952/stage/usr/src/usr.bin/bmake/unit-tests/Makefile" 
line 775: Malformed conditional (${.SHELL:T} == "ksh")

which is 
https://github.com/bruelltuete/freebsd-src/blob/stable/13/usr.bin/bmake/unit-tests/Makefile#L775

Is that expected?

Building releng/13.0 first and using that to build stable/13 works but 
is an extra step I'd like to avoid...


thanks!