diff --git a/release/release.sh b/release/release.sh
index a822d783c59d..7806c036a993 100755
--- a/release/release.sh
+++ b/release/release.sh
@@ -46,249 +46,287 @@ load_chroot_env() { }
 load_target_env() { }
 buildenv_setup() { }
 
-# The directory within which the release will be built.
-CHROOTDIR="/scratch"
-RELENGDIR="$(realpath $(dirname $(basename ${0})))"
-
-# The default version control system command to obtain the sources.
-VCSCMD="svn checkout"
-
-# The default svn checkout server, and svn branches for src/, doc/,
-# and ports/.
-SVNROOT="svn://svn.FreeBSD.org/"
-SRCBRANCH="base/head@rHEAD"
-DOCBRANCH="doc/head@rHEAD"
-PORTBRANCH="ports/head@rHEAD"
-
-# Set for embedded device builds.
-EMBEDDEDBUILD=
-
-# Sometimes one needs to checkout src with --force svn option.
-# If custom kernel configs copied to src tree before checkout, e.g.
-SRC_FORCE_CHECKOUT=
-
-# The default make.conf and src.conf to use.  Set to /dev/null
-# by default to avoid polluting the chroot(8) environment with
-# non-default settings.
-MAKE_CONF="/dev/null"
-SRC_CONF="/dev/null"
-
-# The number of make(1) jobs, defaults to the number of CPUs available for
-# buildworld, and half of number of CPUs available for buildkernel.
-WORLD_FLAGS="-j$(sysctl -n hw.ncpu)"
-KERNEL_FLAGS="-j$(( $(( $(sysctl -n hw.ncpu) + 1 )) / 2))"
-
-MAKE_FLAGS="-s"
-
-# The name of the kernel to build, defaults to GENERIC.
-KERNEL="GENERIC"
-
-# Set to non-empty value to disable checkout of doc/ and/or ports/.  Disabling
-# ports/ checkout also forces NODOC to be set.
-NODOC=
-NOPORTS=
-
-# Set to non-empty value to build dvd1.iso as part of the release.
-WITH_DVD=
-WITH_COMPRESSED_IMAGES=
-
-# Set to non-empty value to build virtual machine images as part of
-# the release.
-WITH_VMIMAGES=
-WITH_COMPRESSED_VMIMAGES=
-XZ_THREADS=0
-
-# Set to non-empty value to build virtual machine images for various
-# cloud providers as part of the release.
-WITH_CLOUDWARE=
-
 usage() {
 	echo "Usage: $0 [-c release.conf]"
 	exit 1
 }
 
-while getopts c: opt; do
-	case ${opt} in
-	c)
-		RELEASECONF="${OPTARG}"
-		if [ ! -e "${RELEASECONF}" ]; then
-			echo "ERROR: Configuration file ${RELEASECONF} does not exist."
-			exit 1
-		fi
-		# Source the specified configuration file for overrides
-		. ${RELEASECONF}
-		;;
-	\?)
-		usage
-		;;
-	esac
-done
-shift $(($OPTIND - 1))
+env_setup() {
+	# The directory within which the release will be built.
+	CHROOTDIR="/scratch"
+	RELENGDIR="$(realpath $(dirname $(basename ${0})))"
 
-# Fix for backwards-compatibility with release.conf that does not have the
-# trailing '/'.
-case ${SVNROOT} in
-	*svn*)
-		SVNROOT="${SVNROOT}/"
-		;;
-	*)
-		;;
-esac
+	# The default version control system command to obtain the sources.
+	VCSCMD="svn checkout"
 
-# Prefix the branches with the SVNROOT for the full checkout URL.
-SRCBRANCH="${SVNROOT}${SRCBRANCH}"
-DOCBRANCH="${SVNROOT}${DOCBRANCH}"
-PORTBRANCH="${SVNROOT}${PORTBRANCH}"
+	# The default svn checkout server, and svn branches for src/, doc/,
+	# and ports/.
+	SVNROOT="svn://svn.FreeBSD.org/"
+	SRCBRANCH="base/head@rHEAD"
+	DOCBRANCH="doc/head@rHEAD"
+	PORTBRANCH="ports/head@rHEAD"
 
-if [ -n "${EMBEDDEDBUILD}" ]; then
+	# Set for embedded device builds.
+	EMBEDDEDBUILD=
+
+	# Sometimes one needs to checkout src with --force svn option.
+	# If custom kernel configs copied to src tree before checkout, e.g.
+	SRC_FORCE_CHECKOUT=
+
+	# The default make.conf and src.conf to use.  Set to /dev/null
+	# by default to avoid polluting the chroot(8) environment with
+	# non-default settings.
+	MAKE_CONF="/dev/null"
+	SRC_CONF="/dev/null"
+
+	# The number of make(1) jobs, defaults to the number of CPUs available for
+	# buildworld, and half of number of CPUs available for buildkernel.
+	WORLD_FLAGS="-j$(sysctl -n hw.ncpu)"
+	KERNEL_FLAGS="-j$(( $(( $(sysctl -n hw.ncpu) + 1 )) / 2))"
+
+	MAKE_FLAGS="-s"
+
+	# The name of the kernel to build, defaults to GENERIC.
+	KERNEL="GENERIC"
+
+	# Set to non-empty value to disable checkout of doc/ and/or ports/.  Disabling
+	# ports/ checkout also forces NODOC to be set.
+	NODOC=
+	NOPORTS=
+
+	# Set to non-empty value to build dvd1.iso as part of the release.
 	WITH_DVD=
 	WITH_COMPRESSED_IMAGES=
-	NODOC=yes
-fi
 
-# If PORTS is set and NODOC is unset, force NODOC=yes because the ports tree
-# is required to build the documentation set.
-if [ -n "${NOPORTS}" ] && [ -z "${NODOC}" ]; then
-	echo "*** NOTICE: Setting NODOC=1 since ports tree is required"
-	echo "            and NOPORTS is set."
-	NODOC=yes
-fi
+	# Set to non-empty value to build virtual machine images as part of
+	# the release.
+	WITH_VMIMAGES=
+	WITH_COMPRESSED_VMIMAGES=
+	XZ_THREADS=0
 
-# If NOPORTS and/or NODOC are unset, they must not pass to make as variables.
-# The release makefile verifies definedness of NOPORTS/NODOC variables
-# instead of their values.
-DOCPORTS=
-if [ -n "${NOPORTS}" ]; then
-	DOCPORTS="NOPORTS=yes "
-fi
-if [ -n "${NODOC}" ]; then
-	DOCPORTS="${DOCPORTS}NODOC=yes"
-fi
+	# Set to non-empty value to build virtual machine images for various
+	# cloud providers as part of the release.
+	WITH_CLOUDWARE=
 
-# The aggregated build-time flags based upon variables defined within
-# this file, unless overridden by release.conf.  In most cases, these
-# will not need to be changed.
-CONF_FILES="__MAKE_CONF=${MAKE_CONF} SRCCONF=${SRC_CONF}"
-if [ -n "${TARGET}" ] && [ -n "${TARGET_ARCH}" ]; then
-	ARCH_FLAGS="TARGET=${TARGET} TARGET_ARCH=${TARGET_ARCH}"
-else
-	ARCH_FLAGS=
-fi
-load_chroot_env
-CHROOT_MAKEENV="${CHROOT_MAKEENV} MAKEOBJDIRPREFIX=${CHROOTDIR}/tmp/obj"
-CHROOT_WMAKEFLAGS="${MAKE_FLAGS} ${WORLD_FLAGS} ${CONF_FILES}"
-CHROOT_IMAKEFLAGS="${CONF_FILES}"
-CHROOT_DMAKEFLAGS="${CONF_FILES}"
-RELEASE_WMAKEFLAGS="${MAKE_FLAGS} ${WORLD_FLAGS} ${ARCH_FLAGS} ${CONF_FILES}"
-RELEASE_KMAKEFLAGS="${MAKE_FLAGS} ${KERNEL_FLAGS} KERNCONF=\"${KERNEL}\" ${ARCH_FLAGS} ${CONF_FILES}"
-RELEASE_RMAKEFLAGS="${ARCH_FLAGS} KERNCONF=\"${KERNEL}\" ${CONF_FILES} \
-	${DOCPORTS} WITH_DVD=${WITH_DVD} WITH_VMIMAGES=${WITH_VMIMAGES} \
-	WITH_CLOUDWARE=${WITH_CLOUDWARE} XZ_THREADS=${XZ_THREADS}"
+	CHROOT_MAKEENV="${CHROOT_MAKEENV} MAKEOBJDIRPREFIX=${CHROOTDIR}/tmp/obj"
+	CHROOT_WMAKEFLAGS="${MAKE_FLAGS} ${WORLD_FLAGS} ${CONF_FILES}"
+	CHROOT_IMAKEFLAGS="${CONF_FILES}"
+	CHROOT_DMAKEFLAGS="${CONF_FILES}"
+	RELEASE_WMAKEFLAGS="${MAKE_FLAGS} ${WORLD_FLAGS} ${ARCH_FLAGS} ${CONF_FILES}"
+	RELEASE_KMAKEFLAGS="${MAKE_FLAGS} ${KERNEL_FLAGS} KERNCONF=\"${KERNEL}\" ${ARCH_FLAGS} ${CONF_FILES}"
+	RELEASE_RMAKEFLAGS="${ARCH_FLAGS} KERNCONF=\"${KERNEL}\" ${CONF_FILES} \
+		${DOCPORTS} WITH_DVD=${WITH_DVD} WITH_VMIMAGES=${WITH_VMIMAGES} \
+		WITH_CLOUDWARE=${WITH_CLOUDWARE} XZ_THREADS=${XZ_THREADS}"
 
-# Force src checkout if configured
-FORCE_SRC_KEY=
-if [ -n "${SRC_FORCE_CHECKOUT}" ]; then
-	FORCE_SRC_KEY="--force"
-fi
+	return 0
+} # env_setup()
 
-if [ -z "${CHROOTDIR}" ]; then
-	echo "Please set CHROOTDIR."
-	exit 1
-fi
+env_check() {
+	# Fix for backwards-compatibility with release.conf that does not have the
+	# trailing '/'.
+	case ${SVNROOT} in
+		*svn*)
+			SVNROOT="${SVNROOT}/"
+			;;
+		*)
+			;;
+	esac
 
-if [ $(id -u) -ne 0 ]; then
-	echo "Needs to be run as root."
-	exit 1
-fi
+	# Prefix the branches with the SVNROOT for the full checkout URL.
+	SRCBRANCH="${SVNROOT}${SRCBRANCH}"
+	DOCBRANCH="${SVNROOT}${DOCBRANCH}"
+	PORTBRANCH="${SVNROOT}${PORTBRANCH}"
 
-set -e # Everything must succeed
+	if [ -n "${EMBEDDEDBUILD}" ]; then
+		WITH_DVD=
+		WITH_COMPRESSED_IMAGES=
+		NODOC=yes
+	fi
 
-mkdir -p ${CHROOTDIR}/usr
+	# If PORTS is set and NODOC is unset, force NODOC=yes because the ports tree
+	# is required to build the documentation set.
+	if [ -n "${NOPORTS}" ] && [ -z "${NODOC}" ]; then
+		echo "*** NOTICE: Setting NODOC=1 since ports tree is required"
+		echo "            and NOPORTS is set."
+		NODOC=yes
+	fi
 
-if [ -z "${SRC_UPDATE_SKIP}" ]; then
-	${VCSCMD} ${FORCE_SRC_KEY} ${SRCBRANCH} ${CHROOTDIR}/usr/src
-fi
-if [ -z "${NODOC}" ] && [ -z "${DOC_UPDATE_SKIP}" ]; then
-	${VCSCMD} ${DOCBRANCH} ${CHROOTDIR}/usr/doc
-fi
-if [ -z "${NOPORTS}" ] && [ -z "${PORTS_UPDATE_SKIP}" ]; then
-	${VCSCMD} ${PORTBRANCH} ${CHROOTDIR}/usr/ports
-fi
+	# If NOPORTS and/or NODOC are unset, they must not pass to make as variables.
+	# The release makefile verifies definedness of NOPORTS/NODOC variables
+	# instead of their values.
+	DOCPORTS=
+	if [ -n "${NOPORTS}" ]; then
+		DOCPORTS="NOPORTS=yes "
+	fi
+	if [ -n "${NODOC}" ]; then
+		DOCPORTS="${DOCPORTS}NODOC=yes"
+	fi
 
-if [ -z "${CHROOTBUILD_SKIP}" ]; then
-	cd ${CHROOTDIR}/usr/src
-	env ${CHROOT_MAKEENV} make ${CHROOT_WMAKEFLAGS} buildworld
-	env ${CHROOT_MAKEENV} make ${CHROOT_IMAKEFLAGS} installworld \
-		DESTDIR=${CHROOTDIR}
-	env ${CHROOT_MAKEENV} make ${CHROOT_DMAKEFLAGS} distribution \
-		DESTDIR=${CHROOTDIR}
-fi
-mount -t devfs devfs ${CHROOTDIR}/dev
-cp /etc/resolv.conf ${CHROOTDIR}/etc/resolv.conf
-trap "umount ${CHROOTDIR}/dev" EXIT # Clean up devfs mount on exit
+	# The aggregated build-time flags based upon variables defined within
+	# this file, unless overridden by release.conf.  In most cases, these
+	# will not need to be changed.
+	CONF_FILES="__MAKE_CONF=${MAKE_CONF} SRCCONF=${SRC_CONF}"
+	if [ -n "${TARGET}" ] && [ -n "${TARGET_ARCH}" ]; then
+		ARCH_FLAGS="TARGET=${TARGET} TARGET_ARCH=${TARGET_ARCH}"
+	else
+		ARCH_FLAGS=
+	fi
+	# Force src checkout if configured
+	FORCE_SRC_KEY=
+	if [ -n "${SRC_FORCE_CHECKOUT}" ]; then
+		FORCE_SRC_KEY="--force"
+	fi
 
-# If MAKE_CONF and/or SRC_CONF are set and not character devices (/dev/null),
-# copy them to the chroot.
-if [ -e ${MAKE_CONF} ] && [ ! -c ${MAKE_CONF} ]; then
-	mkdir -p ${CHROOTDIR}/$(dirname ${MAKE_CONF})
-	cp ${MAKE_CONF} ${CHROOTDIR}/${MAKE_CONF}
-fi
-if [ -e ${SRC_CONF} ] && [ ! -c ${SRC_CONF} ]; then
-	mkdir -p ${CHROOTDIR}/$(dirname ${SRC_CONF})
-	cp ${SRC_CONF} ${CHROOTDIR}/${SRC_CONF}
-fi
+	if [ -z "${CHROOTDIR}" ]; then
+		echo "Please set CHROOTDIR."
+		exit 1
+	fi
 
-# Embedded builds do not use the 'make release' target.
-if [ -n "${EMBEDDEDBUILD}" ]; then
+	if [ $(id -u) -ne 0 ]; then
+		echo "Needs to be run as root."
+		exit 1
+	fi
+
+	return 0
+} # env_check()
+
+chroot_setup() {
+	load_chroot_env
+	mkdir -p ${CHROOTDIR}/usr
+
+	if [ -z "${SRC_UPDATE_SKIP}" ]; then
+		${VCSCMD} ${FORCE_SRC_KEY} ${SRCBRANCH} ${CHROOTDIR}/usr/src
+	fi
+	if [ -z "${NODOC}" ] && [ -z "${DOC_UPDATE_SKIP}" ]; then
+		${VCSCMD} ${DOCBRANCH} ${CHROOTDIR}/usr/doc
+	fi
+	if [ -z "${NOPORTS}" ] && [ -z "${PORTS_UPDATE_SKIP}" ]; then
+		${VCSCMD} ${PORTBRANCH} ${CHROOTDIR}/usr/ports
+	fi
+
+	if [ -z "${CHROOTBUILD_SKIP}" ]; then
+		cd ${CHROOTDIR}/usr/src
+		env ${CHROOT_MAKEENV} make ${CHROOT_WMAKEFLAGS} buildworld
+		env ${CHROOT_MAKEENV} make ${CHROOT_IMAKEFLAGS} installworld \
+			DESTDIR=${CHROOTDIR}
+		env ${CHROOT_MAKEENV} make ${CHROOT_DMAKEFLAGS} distribution \
+			DESTDIR=${CHROOTDIR}
+	fi
+	mount -t devfs devfs ${CHROOTDIR}/dev
+	cp /etc/resolv.conf ${CHROOTDIR}/etc/resolv.conf
+
+	return 0
+} # chroot_setup()
+
+extra_chroot_setup() {
+	# If MAKE_CONF and/or SRC_CONF are set and not character devices (/dev/null),
+	# copy them to the chroot.
+	if [ -e ${MAKE_CONF} ] && [ ! -c ${MAKE_CONF} ]; then
+		mkdir -p ${CHROOTDIR}/$(dirname ${MAKE_CONF})
+		cp ${MAKE_CONF} ${CHROOTDIR}/${MAKE_CONF}
+	fi
+	if [ -e ${SRC_CONF} ] && [ ! -c ${SRC_CONF} ]; then
+		mkdir -p ${CHROOTDIR}/$(dirname ${SRC_CONF})
+		cp ${SRC_CONF} ${CHROOTDIR}/${SRC_CONF}
+	fi
+
+	if [ -d ${CHROOTDIR}/usr/ports ]; then
+		# Run ldconfig(8) in the chroot directory so /var/run/ld-elf*.so.hints
+		# is created.  This is needed by ports-mgmt/pkg.
+		chroot ${CHROOTDIR} /etc/rc.d/ldconfig forcerestart
+
+		## Trick the ports 'run-autotools-fixup' target to do the right thing.
+		_OSVERSION=$(sysctl -n kern.osreldate)
+		REVISION=$(chroot ${CHROOTDIR} make -C /usr/src/release -V REVISION)
+		BRANCH=$(chroot ${CHROOTDIR} make -C /usr/src/release -V BRANCH)
+		UNAME_r=${REVISION}-${BRANCH}
+		if [ -d ${CHROOTDIR}/usr/doc ] && [ -z "${NODOC}" ]; then
+			PBUILD_FLAGS="OSVERSION=${_OSVERSION} BATCH=yes"
+			PBUILD_FLAGS="${PBUILD_FLAGS} UNAME_r=${UNAME_r}"
+			PBUILD_FLAGS="${PBUILD_FLAGS} OSREL=${REVISION}"
+			chroot ${CHROOTDIR} make -C /usr/ports/textproc/docproj \
+				${PBUILD_FLAGS} OPTIONS_UNSET="FOP IGOR" \
+				install clean distclean
+		fi
+	fi
+
+	return 0
+} # extra_chroot_setup()
+
+chroot_build_target() {
 	buildenv_setup
-	# If a crochet configuration file exists in *this* checkout of
-	# release/, copy it to the /tmp/external directory within the chroot.
-	# This allows building embedded releases without relying on updated
-	# scripts and/or configurations to exist in the branch being built.
 	load_target_env
-	if [ -e ${RELENGDIR}/tools/${XDEV}/crochet-${KERNEL}.conf ] && \
-		[ -e ${RELENGDIR}/${XDEV}/release.sh ]; then
-			mkdir -p ${CHROOTDIR}/tmp/external/${XDEV}/
-			cp ${RELENGDIR}/tools/${XDEV}/crochet-${KERNEL}.conf \
-				${CHROOTDIR}/tmp/external/${XDEV}/crochet-${KERNEL}.conf
-			/bin/sh ${RELENGDIR}/${XDEV}/release.sh
+	eval chroot ${CHROOTDIR} make -C /usr/src ${RELEASE_WMAKEFLAGS} buildworld
+	eval chroot ${CHROOTDIR} make -C /usr/src ${RELEASE_KMAKEFLAGS} buildkernel
+
+	# Embedded builds do not use the 'make release' target.
+	if [ -n "${EMBEDDEDBUILD}" ]; then
+		buildenv_setup
+		# If a crochet configuration file exists in *this* checkout of
+		# release/, copy it to the /tmp/external directory within the chroot.
+		# This allows building embedded releases without relying on updated
+		# scripts and/or configurations to exist in the branch being built.
+		load_target_env
+		if [ -e ${RELENGDIR}/tools/${XDEV}/crochet-${KERNEL}.conf ] && \
+			[ -e ${RELENGDIR}/${XDEV}/release.sh ]; then
+				mkdir -p ${CHROOTDIR}/tmp/external/${XDEV}/
+				cp ${RELENGDIR}/tools/${XDEV}/crochet-${KERNEL}.conf \
+					${CHROOTDIR}/tmp/external/${XDEV}/crochet-${KERNEL}.conf
+				/bin/sh ${RELENGDIR}/${XDEV}/release.sh
+		fi
+		# If the script does not exist for this architecture, exit.
+		# This probably should be checked earlier, but allowing the rest
+		# of the build process to get this far will at least set up the
+		# chroot environment for testing.
+		return 1
+	else
+		# Not embedded.
+		return 0
 	fi
-	# If the script does not exist for this architecture, exit.
-	# This probably should be checked earlier, but allowing the rest
-	# of the build process to get this far will at least set up the
-	# chroot environment for testing.
-	exit 0
-else
-	# Not embedded.
-	continue
-fi
 
-if [ -d ${CHROOTDIR}/usr/ports ]; then
-	# Run ldconfig(8) in the chroot directory so /var/run/ld-elf*.so.hints
-	# is created.  This is needed by ports-mgmt/pkg.
-	chroot ${CHROOTDIR} /etc/rc.d/ldconfig forcerestart
+	return 0
+} # chroot_build_target
 
-	## Trick the ports 'run-autotools-fixup' target to do the right thing.
-	_OSVERSION=$(sysctl -n kern.osreldate)
-	REVISION=$(chroot ${CHROOTDIR} make -C /usr/src/release -V REVISION)
-	BRANCH=$(chroot ${CHROOTDIR} make -C /usr/src/release -V BRANCH)
-	UNAME_r=${REVISION}-${BRANCH}
-	if [ -d ${CHROOTDIR}/usr/doc ] && [ -z "${NODOC}" ]; then
-		PBUILD_FLAGS="OSVERSION=${_OSVERSION} BATCH=yes"
-		PBUILD_FLAGS="${PBUILD_FLAGS} UNAME_r=${UNAME_r}"
-		PBUILD_FLAGS="${PBUILD_FLAGS} OSREL=${REVISION}"
-		chroot ${CHROOTDIR} make -C /usr/ports/textproc/docproj \
-			${PBUILD_FLAGS} OPTIONS_UNSET="FOP IGOR" \
-			install clean distclean
-	fi
-fi
+chroot_build_release() {
+	buildenv_setup
+	load_target_env
+	eval chroot ${CHROOTDIR} make -C /usr/src/release ${RELEASE_RMAKEFLAGS} \
+		release
+	eval chroot ${CHROOTDIR} make -C /usr/src/release ${RELEASE_RMAKEFLAGS} \
+		install DESTDIR=/R WITH_COMPRESSED_IMAGES=${WITH_COMPRESSED_IMAGES} \
+		WITH_COMPRESSED_VMIMAGES=${WITH_COMPRESSED_VMIMAGES}
 
-buildenv_setup
-load_target_env
-eval chroot ${CHROOTDIR} make -C /usr/src ${RELEASE_WMAKEFLAGS} buildworld
-eval chroot ${CHROOTDIR} make -C /usr/src ${RELEASE_KMAKEFLAGS} buildkernel
-eval chroot ${CHROOTDIR} make -C /usr/src/release ${RELEASE_RMAKEFLAGS} \
-	release
-eval chroot ${CHROOTDIR} make -C /usr/src/release ${RELEASE_RMAKEFLAGS} \
-	install DESTDIR=/R WITH_COMPRESSED_IMAGES=${WITH_COMPRESSED_IMAGES} \
-	WITH_COMPRESSED_VMIMAGES=${WITH_COMPRESSED_VMIMAGES}
+	return 0
+} # chroot_build_release()
+
+main() {
+	set -e # Everything must succeed
+	env_setup
+	while getopts c: opt; do
+		case ${opt} in
+			c)
+				RELEASECONF="${OPTARG}"
+				if [ ! -e "${RELEASECONF}" ]; then
+					echo "ERROR: Configuration file ${RELEASECONF} does not exist."
+					exit 1
+				fi
+				# Source the specified configuration file for overrides
+				. ${RELEASECONF}
+				;;
+			\?)
+				usage
+				;;
+		esac
+	done
+	shift $(($OPTIND - 1))
+	trap "umount ${CHROOTDIR}/dev" EXIT # Clean up devfs mount on exit
+	env_check
+	chroot_setup
+	extra_chroot_setup
+	chroot_build_target
+	chroot_build_release
+
+	return 0
+} # main()
+
+main "${@}"