ksh supports local
--- ./config/bootstrap.shlib.orig	2018-08-08 23:03:05.000000000 +0200
+++ ./config/bootstrap.shlib	2018-09-21 17:49:28.233607677 +0200
@@ -79,7 +79,7 @@
 else setx=:       dashx=   ; set +x
 fi
 
-test -z "${BASH_VERSION}" && \
+test -z "${BASH_VERSION}" -a -z "${KSH_VERSION}" && \
     local() { "$@" ; }
 
 # Setup run_ag