Building stable/13 on recent stable/12 fails

From: Johannes Totz <>
Date: Sun, 06 Mar 2022 00:28:14 UTC
Hi there,

I'm trying to build stable/13 on a recent stable/12 machine.
But it fails with an error in:
line 775: Malformed conditional (${.SHELL:T} == "ksh")

which is

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...