diff --git a/bin/package b/bin/package
index ecd8fc4d3..06871bf76 100755
--- a/bin/package
+++ b/bin/package
@@ -109,7 +109,7 @@ command=${0##*/}
 case $(getopts '[-][123:xyz]' opt --xyz 2>/dev/null; echo 0$opt) in
 0123)	USAGE=$'
 [-?
-@(#)$Id: '$command$' (ksh 93u+m) 2022-06-12 $
+@(#)$Id: '$command$' (ksh 93u+m) 2022-07-22 $
 ]
 [-author?Glenn Fowler <gsf@research.att.com>]
 [-author?Contributors to https://github.com/ksh93/ksh]
@@ -608,7 +608,7 @@ case $_PACKAGE_HOSTTYPE_ in
 	;;
 esac
 KEEP_PACKAGEROOT=0
-KEEP_SHELL=0
+KEEP_SHELL=0	# set to 1 if SHELL is a known-good system shell, 2 if SHELL supplied by user
 USER_VPATH=
 args=
 assign=
@@ -646,7 +646,7 @@ do	case $i in
 		;;
 	SHELL=*)eval $n='$'v
 		case $SHELL in
-		?*)	KEEP_SHELL=1 ;;
+		?*)	KEEP_SHELL=2 ;;
 		esac
 		;;
 	VPATH=*)eval USER_$n='$'v
@@ -721,7 +721,7 @@ use)	case $1 in
 			$exec export VPATH=$A:$P
 			$exec export nativepp=/usr/lib
 
-			if	test '' != "$INSTALLROOT" -a -d $INSTALLROOT/include/ast
+			if	test -n "$INSTALLROOT" && test -d "$INSTALLROOT/include/ast"
 			then	$exec export PACKAGE_ast=$INSTALLROOT
 			elif	test -d ${PWD%/*}/ast/arch/$HOSTTYPE
 			then	$exec export PACKAGE_ast=${PWD%/*}/ast/arch/$HOSTTYPE
@@ -750,7 +750,7 @@ esac
 
 packageroot() # dir
 {
-	test -d $1/lib/$command -o -x $1/bin/$command
+	test -d "$1/lib/$command" || test -x "$1/bin/$command"
 }
 
 # true if arg is executable
@@ -758,8 +758,8 @@ packageroot() # dir
 executable() # [!] command
 {
 	case $1 in
-	'!')	test ! -x "$2" -a ! -x "$2.exe"; return ;;
-	*)	test -x "$1" -o -x "$1.exe"; return ;;
+	'!')	test ! -x "$2" && test ! -x "$2.exe" ;;
+	*)	test -x "$1" || test -x "$1.exe" ;;
 	esac
 }
 
@@ -1460,7 +1460,7 @@ int main()
 			type=unixware
 			;;
 		UTS*|uts*)
-			if	test -x /bin/u370 -o -x /bin/u390
+			if	test -x /bin/u370 || test -x /bin/u390
 			then	type=uts.390
 			else	case $arch in
 				'')	arch=$mach ;;
@@ -1846,12 +1846,6 @@ esac
 run=-
 case $x in
 1)	: accept the current package use environment
-
-	OK=ok
-	KSH=$EXECROOT/bin/ksh
-	MAKE=mamake
-	SUM=$EXECROOT/bin/sum
-	TEE=$EXECROOT/bin/tee
 	INITROOT=$PACKAGEROOT/src/cmd/INIT
 	checkcc
 	;;
@@ -2261,17 +2255,8 @@ cat $INITROOT/$i.sh
 	$show export EXECROOT
 	export EXECROOT
 
-	# use these if possible
-
-	OK=ok
-	KSH=$EXECROOT/bin/ksh
-	MAKE=mamake
-	SUM=$EXECROOT/bin/sum
-	TEE=$EXECROOT/bin/tee
-
 	# grab a decent default shell
 
-	checksh "$SHELL" || KEEP_SHELL=0
 	case $KEEP_SHELL in
 	0)	save_PATH=$PATH
 		if	PATH=$(getconf PATH 2>/dev/null)
@@ -2506,7 +2491,7 @@ checkaout()	# cmd ...
 	'')	_PACKAGE_cc=0
 		;;
 	*)	_PACKAGE_cc=1
-		test -f $INITROOT/hello.c -a -f $INITROOT/p.c || {
+		test -f "$INITROOT/hello.c" && test -f "$INITROOT/p.c" || {
 			note "$INITROOT: INIT package source not found"
 			return 1
 		}
@@ -2656,7 +2641,7 @@ capture() # file command ...
 			cmd='case $error_status in 0) r=done;; *) r=failed;; esac;'
 			cmd=$cmd' echo "$command: $action $r at $(date) in $INSTALLROOT"'
 			case $quiet in
-			0)	cmd="$cmd 2>&1 | \$TEE -a $o" ;;
+			0)	cmd="$cmd 2>&1 | tee -a $o" ;;
 			*)	cmd="$cmd >> $o" ;;
 			esac
 			trap "$cmd" 0
@@ -2665,10 +2650,7 @@ capture() # file command ...
 			;;
 		esac
 		case $quiet in
-		0)	if	executable ! $TEE
-			then	TEE=tee
-			fi
-			# Connect 'tee' to a FIFO instead of a pipe, so that we can obtain
+		0)	# Connect 'tee' to a FIFO instead of a pipe, so that we can obtain
 			# the build's exit status and use it for $error_status
 			rm -f $o.fifo
 			mkfifo -m 600 $o.fifo || exit
@@ -2677,7 +2659,7 @@ capture() # file command ...
 				# unlink early
 				exec rm $o.fifo
 			) &
-			$TEE -a $o < $o.fifo &
+			tee -a $o < $o.fifo &
 			tee_pid=$!
 			o=$o.fifo
 			;;
@@ -2852,7 +2834,7 @@ make|view)
 	for i in arch arch/$HOSTTYPE
 	do	test -d $PACKAGEROOT/$i || $exec mkdir $PACKAGEROOT/$i || exit
 	done
-	for i in bin bin/$OK bin/$OK/lib fun include lib lib/package lib/package/gen src man man/man1 man/man3 man/man8
+	for i in bin bin/ok bin/ok/lib fun include lib lib/package lib/package/gen src man man/man1 man/man3 man/man8
 	do	test -d $INSTALLROOT/$i || $exec mkdir $INSTALLROOT/$i || exit
 	done
 	make_recurse src
@@ -3054,7 +3036,7 @@ make|view)
 		k=$INITROOT/make.probe
 		case $(ls -t $i $j $k 2>/dev/null) in
 		$i*)	;;
-		*)	if	test -f $j -a -f $k
+		*)	if	test -f "$j" && test -f "$k"
 			then	note "update $i"
 				shellmagic
 				case $exec in
@@ -3087,19 +3069,19 @@ cat $j $k
 	then	execrate=execrate
 		$make cd $INSTALLROOT/bin
 		for i in chmod chgrp cmp cp ln mv rm
-		do	if	test ! -x $OK/$i -a -x /bin/$i.exe
+		do	if	test ! -x "ok/$i" && test -x "/bin/$i.exe"
 			then	shellmagic
 				case $exec in
-				'')	echo "$SHELLMAGIC"'execrate /bin/'$i' "$@"' > $OK/$i
-					chmod +x $OK/$i
+				'')	echo "$SHELLMAGIC"'execrate /bin/'$i' "$@"' > ok/$i
+					chmod +x ok/$i
 					;;
-				*)	$exec echo \'"$SHELLMAGIC"'execrate /bin/'$i' "$@"'\'' >' $OK/$i
-					$exec chmod +x $OK/$i
+				*)	$exec echo \'"$SHELLMAGIC"'execrate /bin/'$i' "$@"'\'' >' ok/$i
+					$exec chmod +x ok/$i
 					;;
 				esac
 			fi
 		done
-		PATH=$INSTALLROOT/bin/$OK:$PATH
+		PATH=$INSTALLROOT/bin/ok:$PATH
 		export PATH
 	else	execrate=
 	fi
@@ -3172,7 +3154,7 @@ cat $j $k
 	# mamprobe data should have been generated by this point
 
 	case $exec in
-	'')	if	test ! -f $INSTALLROOT/bin/.paths -o -w $INSTALLROOT/bin/.paths
+	'')	if	test ! -f "$INSTALLROOT/bin/.paths" || test -w "$INSTALLROOT/bin/.paths"
 		then	N='
 '
 			b= f= h= n= p= u= B= L=
@@ -3264,32 +3246,29 @@ cat $j $k
 			ksh tee cp ln mv rm \
 			*ast*.dll *cmd*.dll *dll*.dll *shell*.dll
 		do	executable $i && {
-				cmp -s $i $OK/$i 2>/dev/null || {
-					test -f $OK/$i &&
-					$exec $execrate $rm $OK/$i </dev/null
-					test -f $OK/$i &&
-					$exec $execrate $mv $OK/$i $OK/$i.old </dev/null
-					test -f $OK/$i &&
+				cmp -s $i ok/$i 2>/dev/null || {
+					test -f ok/$i &&
+					$exec $execrate $rm ok/$i </dev/null
+					test -f ok/$i &&
+					$exec $execrate $mv ok/$i ok/$i.old </dev/null
+					test -f ok/$i &&
 					case $exec:$i in
 					:ksh)
-						err_out "$OK/$i: cannot update [may be in use by a running process] remove manually and try again"
+						err_out "ok/$i: cannot update [may be in use by a running process] remove manually and try again"
 						;;
 					esac
-					$exec $execrate $cp $i $OK/$i
+					$exec $execrate $cp $i ok/$i
 				}
 			}
 		done
-		if	executable $OK/tee
-		then	TEE=$INSTALLROOT/bin/$OK/tee
-		fi
-		if	test "$KEEP_SHELL" != 1 && executable $OK/ksh
-		then	SHELL=$INSTALLROOT/bin/$OK/ksh
+		if	test "$KEEP_SHELL" -eq 0 && executable ok/ksh
+		then	SHELL=$INSTALLROOT/bin/ok/ksh
 			export SHELL
 		fi
 		case :$PATH: in
-		*:$INSTALLROOT/bin/$OK:*)
+		*:$INSTALLROOT/bin/ok:*)
 			;;
-		*)	PATH=$INSTALLROOT/bin/$OK:$PATH
+		*)	PATH=$INSTALLROOT/bin/ok:$PATH
 			export PATH
 			;;
 		esac
@@ -3371,10 +3350,6 @@ results)set '' $target
 			;;
 		make|test|view)
 			def=$1
-			case $filter:$1:$SHELL in
-			errors:*:*)	;;
-			*:test:*/ksh*)	filter=rt ;;
-			esac
 			;;
 		old)	suf=old
 			;;
@@ -3391,7 +3366,6 @@ results)set '' $target
 		path)	path=1
 			;;
 		test)	def=test
-			filter=rt
 			;;
 		*)	break
 			;;
@@ -3444,8 +3418,6 @@ results)set '' $target
 					;;
 				errors)	$exec egrep -i '\*\*\*|FAIL[ES]|^TEST.* [123456789][0123456789]* error|core.*dump' $j | sed -e '/^TEST.\//s,/[^ ]*/,,'
 					;;
-				rt)	$exec $KSH rt - $j
-					;;
 				*)	$exec egrep -i '^TEST|FAIL' $j
 					;;
 				esac
@@ -3489,8 +3461,14 @@ results)set '' $target
 	esac
 	;;
 
-test)	# run all available default regression tests
+test)	# run all available default regression tests, using our newly compiled shell unless overridden
+
 	cd "$INSTALLROOT" || err_out "run '$0 make' first"
+	if	test "$KEEP_SHELL" -lt 2
+	then	executable bin/ksh || err_out "build ksh first, or supply a SHELL=/path/to/ksh argument"
+		SHELL=$INSTALLROOT/bin/ksh
+	fi
+	export SHELL
 	set -f
 	set -- ${args:-src}
 	cd "$1" || exit
diff --git a/src/cmd/INIT/Mamfile b/src/cmd/INIT/Mamfile
index dc853f9cb..e9998dbe3 100644
--- a/src/cmd/INIT/Mamfile
+++ b/src/cmd/INIT/Mamfile
@@ -159,42 +159,6 @@ make install
 		exec - esac
 		exec - test -w regress -a -x regress || chmod u+w,+x regress
 	done regress generated
-	make rt
-		make rt.sh
-		done rt.sh
-		prev rt.sh
-		exec - case static,port:$OPTIND:$RANDOM in
-		exec - ?*:*:*|*::*|*:*:$RANDOM)
-		exec - ;;
-		exec - *) if ENV= LC_ALL=C x= $SHELL -nc '[[ a || b ]] && : ${list[level]}  !(pattern)' 2>/dev/null
-		exec - then if grep '### .*archaic.* ###' >/dev/null
-		exec - then : rt contains archaic constructs :
-		exec - else ENV= LC_ALL=C $SHELL -n rt.sh
-		exec - fi
-		exec - fi
-		exec - ;;
-		exec - esac
-		exec - case '${mam_cc_SHELLMAGIC}' in
-		exec - "") case 184 in
-		exec - 0) cp rt.sh rt
-		exec - ;;
-		exec - *) {
-		exec - i=`(read x; echo $x) < rt.sh`
-		exec - case $i in
-		exec - '#!'*|*'||'*|':'*|'":"'*|"':'"*) echo "$i" ;;
-		exec - esac
-		exec - cat rt.sh
-		exec - } > rt
-		exec - ;;
-		exec - esac
-		exec - ;;
-		exec - *) cat - rt.sh > rt <<'!'
-		exec - ${mam_cc_SHELLMAGIC}
-		exec - !
-		exec - ;;
-		exec - esac
-		exec - test -w rt -a -x rt || chmod u+w,+x rt
-	done rt generated
 	make crossexec
 		make crossexec.sh
 		done crossexec.sh
@@ -498,10 +462,6 @@ make install
 		prev regress
 		exec - test '' = 'regress' || ${STDCMP} 2>/dev/null -s regress ${INSTALLROOT}/bin/regress || { ${STDMV} ${INSTALLROOT}/bin/regress ${INSTALLROOT}/bin/regress.old 2>/dev/null || true; ${STDCP} regress ${INSTALLROOT}/bin/regress ;}
 	done ${INSTALLROOT}/bin/regress generated
-	make ${INSTALLROOT}/bin/rt
-		prev rt
-		exec - test '' = 'rt' || ${STDCMP} 2>/dev/null -s rt ${INSTALLROOT}/bin/rt || { ${STDMV} ${INSTALLROOT}/bin/rt ${INSTALLROOT}/bin/rt.old 2>/dev/null || true; ${STDCP} rt ${INSTALLROOT}/bin/rt ;}
-	done ${INSTALLROOT}/bin/rt generated
 	make ${PACKAGEROOT}/bin
 		exec - if test ! -d ${PACKAGEROOT}/bin
 		exec - then mkdir -p ${PACKAGEROOT}/bin
@@ -1095,16 +1055,16 @@ make test
 	make test.iffe
 		make iffe.tst
 		done iffe.tst
-		exec - regress iffe.tst iffe
+		exec - exec "$SHELL" "$INSTALLROOT/bin/regress" iffe.tst iffe
 	done test.iffe virtual
 	make test.mamake
 		make mamake.tst
 			make mamake.rt
 			done mamake.rt
-			exec - if [[ "1" || "mamake.rt" -nt "mamake.tst" ]]
-			exec - then mktest --style=regress mamake.rt > mamake.tst
+			exec - if test mamake.rt -nt mamake.tst
+			exec - then "$SHELL" "$INSTALLROOT/bin/mktest" --style=regress mamake.rt > mamake.tst
 			exec - fi
 		done mamake.tst generated
-		exec - regress mamake.tst mamake
+		exec - exec "$SHELL" "$INSTALLROOT/bin/regress" mamake.tst mamake
 	done test.mamake virtual
 done test dontcare virtual
diff --git a/src/cmd/INIT/package.sh b/src/cmd/INIT/package.sh
index ecd8fc4d3..06871bf76 100644
--- a/src/cmd/INIT/package.sh
+++ b/src/cmd/INIT/package.sh
@@ -109,7 +109,7 @@ command=${0##*/}
 case $(getopts '[-][123:xyz]' opt --xyz 2>/dev/null; echo 0$opt) in
 0123)	USAGE=$'
 [-?
-@(#)$Id: '$command$' (ksh 93u+m) 2022-06-12 $
+@(#)$Id: '$command$' (ksh 93u+m) 2022-07-22 $
 ]
 [-author?Glenn Fowler <gsf@research.att.com>]
 [-author?Contributors to https://github.com/ksh93/ksh]
@@ -608,7 +608,7 @@ case $_PACKAGE_HOSTTYPE_ in
 	;;
 esac
 KEEP_PACKAGEROOT=0
-KEEP_SHELL=0
+KEEP_SHELL=0	# set to 1 if SHELL is a known-good system shell, 2 if SHELL supplied by user
 USER_VPATH=
 args=
 assign=
@@ -646,7 +646,7 @@ do	case $i in
 		;;
 	SHELL=*)eval $n='$'v
 		case $SHELL in
-		?*)	KEEP_SHELL=1 ;;
+		?*)	KEEP_SHELL=2 ;;
 		esac
 		;;
 	VPATH=*)eval USER_$n='$'v
@@ -721,7 +721,7 @@ use)	case $1 in
 			$exec export VPATH=$A:$P
 			$exec export nativepp=/usr/lib
 
-			if	test '' != "$INSTALLROOT" -a -d $INSTALLROOT/include/ast
+			if	test -n "$INSTALLROOT" && test -d "$INSTALLROOT/include/ast"
 			then	$exec export PACKAGE_ast=$INSTALLROOT
 			elif	test -d ${PWD%/*}/ast/arch/$HOSTTYPE
 			then	$exec export PACKAGE_ast=${PWD%/*}/ast/arch/$HOSTTYPE
@@ -750,7 +750,7 @@ esac
 
 packageroot() # dir
 {
-	test -d $1/lib/$command -o -x $1/bin/$command
+	test -d "$1/lib/$command" || test -x "$1/bin/$command"
 }
 
 # true if arg is executable
@@ -758,8 +758,8 @@ packageroot() # dir
 executable() # [!] command
 {
 	case $1 in
-	'!')	test ! -x "$2" -a ! -x "$2.exe"; return ;;
-	*)	test -x "$1" -o -x "$1.exe"; return ;;
+	'!')	test ! -x "$2" && test ! -x "$2.exe" ;;
+	*)	test -x "$1" || test -x "$1.exe" ;;
 	esac
 }
 
@@ -1460,7 +1460,7 @@ int main()
 			type=unixware
 			;;
 		UTS*|uts*)
-			if	test -x /bin/u370 -o -x /bin/u390
+			if	test -x /bin/u370 || test -x /bin/u390
 			then	type=uts.390
 			else	case $arch in
 				'')	arch=$mach ;;
@@ -1846,12 +1846,6 @@ esac
 run=-
 case $x in
 1)	: accept the current package use environment
-
-	OK=ok
-	KSH=$EXECROOT/bin/ksh
-	MAKE=mamake
-	SUM=$EXECROOT/bin/sum
-	TEE=$EXECROOT/bin/tee
 	INITROOT=$PACKAGEROOT/src/cmd/INIT
 	checkcc
 	;;
@@ -2261,17 +2255,8 @@ cat $INITROOT/$i.sh
 	$show export EXECROOT
 	export EXECROOT
 
-	# use these if possible
-
-	OK=ok
-	KSH=$EXECROOT/bin/ksh
-	MAKE=mamake
-	SUM=$EXECROOT/bin/sum
-	TEE=$EXECROOT/bin/tee
-
 	# grab a decent default shell
 
-	checksh "$SHELL" || KEEP_SHELL=0
 	case $KEEP_SHELL in
 	0)	save_PATH=$PATH
 		if	PATH=$(getconf PATH 2>/dev/null)
@@ -2506,7 +2491,7 @@ checkaout()	# cmd ...
 	'')	_PACKAGE_cc=0
 		;;
 	*)	_PACKAGE_cc=1
-		test -f $INITROOT/hello.c -a -f $INITROOT/p.c || {
+		test -f "$INITROOT/hello.c" && test -f "$INITROOT/p.c" || {
 			note "$INITROOT: INIT package source not found"
 			return 1
 		}
@@ -2656,7 +2641,7 @@ capture() # file command ...
 			cmd='case $error_status in 0) r=done;; *) r=failed;; esac;'
 			cmd=$cmd' echo "$command: $action $r at $(date) in $INSTALLROOT"'
 			case $quiet in
-			0)	cmd="$cmd 2>&1 | \$TEE -a $o" ;;
+			0)	cmd="$cmd 2>&1 | tee -a $o" ;;
 			*)	cmd="$cmd >> $o" ;;
 			esac
 			trap "$cmd" 0
@@ -2665,10 +2650,7 @@ capture() # file command ...
 			;;
 		esac
 		case $quiet in
-		0)	if	executable ! $TEE
-			then	TEE=tee
-			fi
-			# Connect 'tee' to a FIFO instead of a pipe, so that we can obtain
+		0)	# Connect 'tee' to a FIFO instead of a pipe, so that we can obtain
 			# the build's exit status and use it for $error_status
 			rm -f $o.fifo
 			mkfifo -m 600 $o.fifo || exit
@@ -2677,7 +2659,7 @@ capture() # file command ...
 				# unlink early
 				exec rm $o.fifo
 			) &
-			$TEE -a $o < $o.fifo &
+			tee -a $o < $o.fifo &
 			tee_pid=$!
 			o=$o.fifo
 			;;
@@ -2852,7 +2834,7 @@ make|view)
 	for i in arch arch/$HOSTTYPE
 	do	test -d $PACKAGEROOT/$i || $exec mkdir $PACKAGEROOT/$i || exit
 	done
-	for i in bin bin/$OK bin/$OK/lib fun include lib lib/package lib/package/gen src man man/man1 man/man3 man/man8
+	for i in bin bin/ok bin/ok/lib fun include lib lib/package lib/package/gen src man man/man1 man/man3 man/man8
 	do	test -d $INSTALLROOT/$i || $exec mkdir $INSTALLROOT/$i || exit
 	done
 	make_recurse src
@@ -3054,7 +3036,7 @@ make|view)
 		k=$INITROOT/make.probe
 		case $(ls -t $i $j $k 2>/dev/null) in
 		$i*)	;;
-		*)	if	test -f $j -a -f $k
+		*)	if	test -f "$j" && test -f "$k"
 			then	note "update $i"
 				shellmagic
 				case $exec in
@@ -3087,19 +3069,19 @@ cat $j $k
 	then	execrate=execrate
 		$make cd $INSTALLROOT/bin
 		for i in chmod chgrp cmp cp ln mv rm
-		do	if	test ! -x $OK/$i -a -x /bin/$i.exe
+		do	if	test ! -x "ok/$i" && test -x "/bin/$i.exe"
 			then	shellmagic
 				case $exec in
-				'')	echo "$SHELLMAGIC"'execrate /bin/'$i' "$@"' > $OK/$i
-					chmod +x $OK/$i
+				'')	echo "$SHELLMAGIC"'execrate /bin/'$i' "$@"' > ok/$i
+					chmod +x ok/$i
 					;;
-				*)	$exec echo \'"$SHELLMAGIC"'execrate /bin/'$i' "$@"'\'' >' $OK/$i
-					$exec chmod +x $OK/$i
+				*)	$exec echo \'"$SHELLMAGIC"'execrate /bin/'$i' "$@"'\'' >' ok/$i
+					$exec chmod +x ok/$i
 					;;
 				esac
 			fi
 		done
-		PATH=$INSTALLROOT/bin/$OK:$PATH
+		PATH=$INSTALLROOT/bin/ok:$PATH
 		export PATH
 	else	execrate=
 	fi
@@ -3172,7 +3154,7 @@ cat $j $k
 	# mamprobe data should have been generated by this point
 
 	case $exec in
-	'')	if	test ! -f $INSTALLROOT/bin/.paths -o -w $INSTALLROOT/bin/.paths
+	'')	if	test ! -f "$INSTALLROOT/bin/.paths" || test -w "$INSTALLROOT/bin/.paths"
 		then	N='
 '
 			b= f= h= n= p= u= B= L=
@@ -3264,32 +3246,29 @@ cat $j $k
 			ksh tee cp ln mv rm \
 			*ast*.dll *cmd*.dll *dll*.dll *shell*.dll
 		do	executable $i && {
-				cmp -s $i $OK/$i 2>/dev/null || {
-					test -f $OK/$i &&
-					$exec $execrate $rm $OK/$i </dev/null
-					test -f $OK/$i &&
-					$exec $execrate $mv $OK/$i $OK/$i.old </dev/null
-					test -f $OK/$i &&
+				cmp -s $i ok/$i 2>/dev/null || {
+					test -f ok/$i &&
+					$exec $execrate $rm ok/$i </dev/null
+					test -f ok/$i &&
+					$exec $execrate $mv ok/$i ok/$i.old </dev/null
+					test -f ok/$i &&
 					case $exec:$i in
 					:ksh)
-						err_out "$OK/$i: cannot update [may be in use by a running process] remove manually and try again"
+						err_out "ok/$i: cannot update [may be in use by a running process] remove manually and try again"
 						;;
 					esac
-					$exec $execrate $cp $i $OK/$i
+					$exec $execrate $cp $i ok/$i
 				}
 			}
 		done
-		if	executable $OK/tee
-		then	TEE=$INSTALLROOT/bin/$OK/tee
-		fi
-		if	test "$KEEP_SHELL" != 1 && executable $OK/ksh
-		then	SHELL=$INSTALLROOT/bin/$OK/ksh
+		if	test "$KEEP_SHELL" -eq 0 && executable ok/ksh
+		then	SHELL=$INSTALLROOT/bin/ok/ksh
 			export SHELL
 		fi
 		case :$PATH: in
-		*:$INSTALLROOT/bin/$OK:*)
+		*:$INSTALLROOT/bin/ok:*)
 			;;
-		*)	PATH=$INSTALLROOT/bin/$OK:$PATH
+		*)	PATH=$INSTALLROOT/bin/ok:$PATH
 			export PATH
 			;;
 		esac
@@ -3371,10 +3350,6 @@ results)set '' $target
 			;;
 		make|test|view)
 			def=$1
-			case $filter:$1:$SHELL in
-			errors:*:*)	;;
-			*:test:*/ksh*)	filter=rt ;;
-			esac
 			;;
 		old)	suf=old
 			;;
@@ -3391,7 +3366,6 @@ results)set '' $target
 		path)	path=1
 			;;
 		test)	def=test
-			filter=rt
 			;;
 		*)	break
 			;;
@@ -3444,8 +3418,6 @@ results)set '' $target
 					;;
 				errors)	$exec egrep -i '\*\*\*|FAIL[ES]|^TEST.* [123456789][0123456789]* error|core.*dump' $j | sed -e '/^TEST.\//s,/[^ ]*/,,'
 					;;
-				rt)	$exec $KSH rt - $j
-					;;
 				*)	$exec egrep -i '^TEST|FAIL' $j
 					;;
 				esac
@@ -3489,8 +3461,14 @@ results)set '' $target
 	esac
 	;;
 
-test)	# run all available default regression tests
+test)	# run all available default regression tests, using our newly compiled shell unless overridden
+
 	cd "$INSTALLROOT" || err_out "run '$0 make' first"
+	if	test "$KEEP_SHELL" -lt 2
+	then	executable bin/ksh || err_out "build ksh first, or supply a SHELL=/path/to/ksh argument"
+		SHELL=$INSTALLROOT/bin/ksh
+	fi
+	export SHELL
 	set -f
 	set -- ${args:-src}
 	cd "$1" || exit
diff --git a/src/cmd/INIT/rt.sh b/src/cmd/INIT/rt.sh
deleted file mode 100644
index 84484a7c9..000000000
--- a/src/cmd/INIT/rt.sh
+++ /dev/null
@@ -1,482 +0,0 @@
-########################################################################
-#                                                                      #
-#               This software is part of the ast package               #
-#          Copyright (c) 1994-2011 AT&T Intellectual Property          #
-#          Copyright (c) 2020-2021 Contributors to ksh 93u+m           #
-#                      and is licensed under the                       #
-#                 Eclipse Public License, Version 1.0                  #
-#                    by AT&T Intellectual Property                     #
-#                                                                      #
-#                A copy of the License is available at                 #
-#          http://www.eclipse.org/org/documents/epl-v10.html           #
-#         (with md5 checksum b35adb5213ca9657e911e9befb180842)         #
-#                                                                      #
-#              Information and Software Systems Research               #
-#                            AT&T Research                             #
-#                           Florham Park NJ                            #
-#                                                                      #
-#                 Glenn Fowler <gsf@research.att.com>                  #
-#                                                                      #
-########################################################################
-: rt - nmake test output filter
-
-command=rt
-flags='--silent --keepgoing'
-failed=0
-heading=1
-verbose=0
-
-case `(getopts '[-][123:xyz]' opt --xyz; echo 0$opt) 2>/dev/null` in
-0123)	ARGV0="-a $command"
-	USAGE=$'
-[-?
-@(#)$Id: rt (AT&T Research) 2010-07-27 $
-]
-[-author?Glenn Fowler <gsf@research.att.com>]
-[-copyright?Copyright (c) 2005-2012 AT&T Intellectual Property]
-[-license?http://www.eclipse.org/org/documents/epl-v10.html]
-[+NAME?rt - run "nmake test" and filter output]
-[+DESCRIPTION?\brt\b runs \bnmake test\b and filters the regression
-	test output to contain only test summary lines. If no \atest\a
-	operands are specified then \btest\b is assumed. If \b-\b is
-	specified then the \afile\a operands, or the standard input
-	if no \afile\a operands are specified, are filtered instead
-	of the output from \bnmake\b.]
-[f:failed?Only list failed test results.]
-[h!:heading?Enable per-file heading when more than one \afile\a operand
-	follows \b-\b.]
-[v:verbose?Run with \bREGRESSFLAGS=-v\b.]
-
-[ test ... | - [ file ... ] ]
-
-[+SEE ALSO?\bnmake\b(1), \bregress\b(1)]
-[+CAVEATS?\brt\b guesses the regression test output style. Garbled
-	output indicates a bad guess.]
-'
-	;;
-*)	ARGV0=""
-	USAGE="fhv"
-	;;
-esac
-
-function usage
-{
-	OPTIND=0
-	getopts $ARGV0 "$USAGE" OPT '-?'
-	exit 2
-}
-
-while	getopts $ARGV0 "$USAGE" OPT
-do	case $OPT in
-	f)	failed=1 ;;
-	h)	heading=0 ;;
-	v)	(( verbose=$OPTARG )) && flags="$flags REGRESSFLAGS=-v" ;;
-	esac
-done
-shift `expr $OPTIND - 1`
-
-ifs=${IFS:-$' \t\n'}
-set -o noglob
-component=
-dots='............................................'
-bad=' ***'
-style=unknown
-integer tests errors signals lineno=0 skip=0
-typeset -l lower
-
-function results # tests errors signals
-{
-	integer t=$1 e=$2 s=$3
-	typeset label note
-	if	[[ $style != unknown ]] && (( errors >= 0 ))
-	then	style=unknown
-		if	(( !failed || errors ))
-		then	if	(( failed ))
-			then	print -r -n -- "$unit"
-			fi
-			if	(( t >= 0 ))
-			then	if	(( t == 1))
-				then	label="test "
-				else	label=tests
-				fi
-				printf $'%s%5d %s' "$prefix" "$t" "$label"
-				prefix=
-			else	prefix="$prefix..........."
-			fi
-			if	(( s ))
-			then	label=signal
-				(( e=s ))
-			else	label=error
-			fi
-			if	(( e != 1))
-			then	label=${label}s
-			fi
-			if	(( e == 1 ))
-			then	note=" $bad"
-			elif	(( e > 1 ))
-			then	note=$bad
-			fi
-			printf $'%s%5d %s%s\n' "$prefix" "$e" "$label" "$note"
-		fi
-	fi
-}
-
-function unit
-{
-	typeset x
-	if	[[ $component ]]
-	then	x=${component##*/}
-		if	[[ " $x " != *' '$unit' '* && " $unit " != *' '$x' '* ]]
-		then	if	[[ $component == cmd/?*lib/* ]]
-			then	unit="$unit $x"
-			else	unit="$x $unit"
-			fi
-		fi
-	fi
-	unit="$unit ${dots:1:${#dots}-${#unit}}"
-	if	[[ $1 ]]
-	then	unit="$unit..........."
-	fi
-	if	(( ! failed ))
-	then	print -r -n -- "$unit"
-	fi
-}
-
-if	[[ $1 == - ]]
-then	shift
-	if	(( $# <= 1 ))
-	then	heading=0
-	fi
-	if	(( heading ))
-	then	for i
-		do	print test heading $i
-			cat -- "$i"
-		done
-	else	cat "$@"
-	fi
-else	if	[[ $1 == *=* ]]
-	then	set test "$@"
-	elif	(( ! $# ))
-	then	set test
-	fi
-	nmake "$@" $flags 2>&1
-fi |
-while	read -r line
-do	set '' $line
-	shift
-	case $line in
-	TEST[' 	']*', '*' error'*)
-		IFS=${IFS}","
-		set '' $line
-		IFS=$ifs
-		set '' $*
-		while	:
-		do	case $2 in
-			'')	break
-				;;
-			error|errors)
-				errors=$1
-				break
-				;;
-			test|tests)
-				tests=$1
-				;;
-			esac
-			shift
-		done
-		results $tests $errors
-		continue
-		;;
-	TEST[' 	']*)
-		results $tests $errors
-		IFS=${IFS}","
-		set '' $line
-		IFS=$ifs
-		set '' $*
-		unit=${3##*/}
-		case $4 in
-		[a-zA-Z]*)	unit="$unit $4" ;;
-		esac
-		unit
-		prefix=
-		errors=0
-		signals=0
-		style=regress
-		continue
-		;;
-	'pathname and options of item under test')
-		read -r line || break
-		results $tests $errors $signals
-		set '' $line
-		unit=${2##*/}
-		unit
-		tests=0
-		errors=0
-		signals=0
-		style=script
-		continue
-		;;
-	'test heading '*)
-		if	(( heading ))
-		then	if	(( heading > 1 ))
-			then	print
-			else	heading=2
-			fi
-			set '' $line
-			shift 3
-			print -r -- "==> $* <=="
-		fi
-		continue
-		;;
-	'test '*' begins at '????-??-??+??:??:??|'test '*' begins at '*' '*' '*' '*' '*)
-		results $tests $errors $signals
-		unit=${2##*/}
-		unit=${unit%.sh}
-		unit
-		prefix=
-		tests=-1
-		errors=0
-		signals=0
-		style=shell
-		continue
-		;;
-	'test '*' at '????-??-??+??:??:??' [ '*' ]'|'test '*' at '*' '*' '*' '*' '*)
-		case $line in
-		*' [ '*test*error*' ]')
-			while	:
-			do	case $1 in
-				'[')	tests=$2
-					errors=$4
-					if	(( errors > 256 ))
-					then	(( signals++ ))
-					fi
-					break
-					;;
-				esac
-				shift
-			done
-			;;
-		*' [ '*test*signal*' ]')
-			while	:
-			do	case $1 in
-				'[')	tests=$2
-					signals=$4
-					if	(( signals ))
-					then	(( errors++ ))
-					fi
-					break
-					;;
-				esac
-				shift
-			done
-			;;
-		*)	if	[[ $3 != passed ]]
-			then	(( errors )) || (( errors++ ))
-			fi
-			;;
-		esac
-		results $tests $errors $signals
-		continue
-		;;
-	'## ---'*(-)'--- ##')
-		(( ++lineno > skip )) || continue
-		read -r line || break
-		lower=$line
-		set '' $lower
-		case $lower in
-		'##'*'test suite:'*'##')
-			results $tests $errors $signals
-			set -- ${lower//*suite:}
-			set -- ${*//[.#]/}
-			unit=$*
-			if	[[ $unit == *' tests' ]]
-			then	unit=${unit/' tests'/}
-			fi
-			main=$unit
-			prefix=
-			tests=0
-			errors=0
-			signals=0
-			category=
-			style=autotest
-			(( skip = lineno + 1 ))
-			unit
-			continue
-			;;
-		esac
-		;;
-	+(-))	case $style in
-		regress)	continue ;;
-		esac
-		(( ++lineno > skip )) || continue
-		read -r line || break
-		set '' $line
-		case $line in
-		'Running tests for '*)
-			results $tests $errors $signals
-			shift 4
-			unit=
-			while	(( $# ))
-			do	if	[[ $1 == on ]]
-				then	break
-				fi
-				if	[[ $unit ]]
-				then	unit="$unit "
-				fi
-				unit=$unit${1##*/}
-				shift
-			done
-			main=$unit
-			prefix=
-			tests=-1
-			errors=-1
-			category=
-			style=perl
-			(( skip = lineno + 1 ))
-			continue
-			;;
-		*' : '*)results $tests $errors $signals
-			unit=${2##*/}
-			unit=${unit%.sh}
-			unit
-			prefix=
-			tests=0
-			errors=0
-			signals=0
-			style=timing
-			(( skip = lineno + 1 ))
-			continue
-			;;
-		esac
-		;;
-	+([0-9])*([a-zA-Z0-9])' '*)
-		case $style in
-		script)	case $line in
-			*FAILED*|*failed*)
-				(( errors++ ))
-				;;
-			*)	(( tests++ ))
-				;;
-			esac
-			;;
-		esac
-		;;
-	make:*|'make ['*']:'*)
-		case $line in
-		*': warning:'*|*'making test'*|*'action'?(s)' failed'*|*': *** '*)
-			;;
-		*)	results $tests $errors $signals
-			print -r -u2 -- "$line"
-			;;
-		esac
-		continue
-		;;
-	+([/a-zA-Z_0-9]):)
-		component=${line%:}
-		;;
-	'')	continue
-		;;
-	esac
-	case $style in
-	autotest)
-		case $line in
-		+([0-9]):*ok)
-			(( tests++ ))
-			;;
-		+([0-9]):*FAILED*)
-			(( tests++ ))
-			(( errors++ ))
-			if	(( $verbose ))
-			then	if	[[ ! $prefix ]]
-				then	prefix=$unit
-					print
-				fi
-				print -r -- "	${line//*'FAILED '/}"
-			fi
-			;;
-		esac
-		continue
-		;;
-	perl)	case $line in
-		*'........ '*)
-			if	[[ $1 == */* ]]
-			then	cat=${1%%/*}
-				if	[[ $cat != $category ]]
-				then	results $tests $errors $signals
-					category=$cat
-					unit="$main $category"
-					unit
-					prefix=
-					tests=0
-					errors=0
-					signals=0
-				fi
-				(( tests++ ))
-				case $line in
-				*' ok')	;;
-				*)	(( errors++ ))
-					if	(( $verbose ))
-					then	if	[[ ! $prefix ]]
-						then	prefix=$unit
-							print
-						fi
-						print -r -- "$line"
-					fi
-					;;
-				esac
-			else	results $tests $errors $signals
-				case $line in
-				*' ok')	errors=0 ;;
-				*)	errors=1 ;;
-				esac
-				unit="$main $1"
-				unit
-				if	(( $verbose && errors ))
-				then	prefix=$unit
-					print
-					shift 2
-					print -r -- "$@"
-				else	prefix=
-				fi
-				results $tests $errors $signals
-				tests=-1
-				errors=-1
-				category=
-			fi
-			style=perl
-			;;
-		esac
-		continue
-		;;
-	esac
-	case $line in
-	*FAILED*|*failed*)
-		(( errors++ ))
-		;;
-	*)	case $style in
-		regress)case $line in
-			['<>']*);;
-			*)	continue ;;
-			esac
-			;;
-		script)	continue
-			;;
-		shell)	((errors++ ))
-			;;
-		timing)	(( tests++ ))
-			continue
-			;;
-		unknown)continue
-			;;
-		esac
-		;;
-	esac
-	if	(( $verbose ))
-	then	if	[[ ! $prefix ]]
-		then	prefix=$unit
-			print
-		fi
-		print -r -- "$line"
-	fi
-done
-results $tests $errors $signals
diff --git a/src/cmd/ksh93/Mamfile b/src/cmd/ksh93/Mamfile
index 516c9be90..0ed601706 100644
--- a/src/cmd/ksh93/Mamfile
+++ b/src/cmd/ksh93/Mamfile
@@ -1467,6 +1467,6 @@ make test
 		make tests/shtests
 		done tests/shtests
 		exec - cd "$PACKAGEROOT/src/cmd/ksh93/tests"
-		exec - SHELL=$INSTALLROOT/bin/ksh "$INSTALLROOT/bin/ksh" ./shtests
+		exec - exec "$SHELL" shtests
 	done test.ksh virtual
 done test dontcare virtual