General cleanup, pt. II.

29 files changed, 589 insertions, 480 deletions

diff --git a/subr/build_init.subr b/subr/build_init.subr
index a52ff5ff..a1c4f78d 100644
--- a/subr/build_init.subr
+++ b/subr/build_init.subr
@@ -1,14 +1,6 @@
-buildp_ast() {
-	local _param="${1}" _pids_killed="";
-	rm -f "${DEFAULT_BUILD_STATUS_IN_PROGRESS_FNAME}";
-	case "${_param}" in
-	abort) ex_rtl_log_msg failexit "Build aborted."; ;;
-	esac;
-	ex_rtl_kill_tree "${$}";
-	if [ -n "${_pids_killed}" ]; then
-		ex_rtl_log_msg vnfo "Killed PIDs ${_pids_killed}";
-	fi;
-};
+#
+# set +o errexit -o noglob is assumed.
+#
 
 buildp_init_args() {
 	local _last_pkg=""; _status="";
@@ -25,8 +17,8 @@ buildp_init_args() {
 		fi;
 	fi;
 	case "${ARG_RESTART}" in
-	ALL)	ARG_RESTART_AT=ALL; ;;
-	LAST)	ARG_RESTART_AT=""; ;;
+	ALL)	ARG_RESTART_AT=ALL; ARG_RESTART_RECURSIVE=2; ;;
+	LAST)	ARG_RESTART_AT=ALL; ARG_RESTART_RECURSIVE=0; ;;
 	"")	;;
 	*:*)	ARG_RESTART_AT="${ARG_RESTART#*:}"; ARG_RESTART="${ARG_RESTART%:*}"; ;;
 	*)	ARG_RESTART="$(echo "${ARG_RESTART}" | sed "s/,/ /g")"; ARG_RESTART_AT=ALL; ;;
@@ -35,87 +27,116 @@ buildp_init_args() {
 		if [ -n "${DEFAULT_BUILD_LAST_FAILED_PKG_FNAME}" ]\
 		&& [ -e "${DEFAULT_BUILD_LAST_FAILED_PKG_FNAME}" ]; then
 			_last_pkg="$(cat "${DEFAULT_BUILD_LAST_FAILED_PKG_FNAME}")";
-			ex_rtl_fileop rm "${DEFAULT_BUILD_LAST_FAILED_PKG_FNAME}";
-			ex_rtl_state_clear "${BUILD_WORKDIR}" "${_last_pkg}";
+			rtl_fileop rm "${DEFAULT_BUILD_LAST_FAILED_PKG_FNAME}";
+			rtl_state_clear "${BUILD_WORKDIR}" "${_last_pkg}";
+			ARG_RESTART="${_last_pkg}";
 		fi;
 	fi;
-	ex_rtl_log_set_vnfo_lvl "${ARG_VERBOSE:-0}";
-	BUILD_DATE_START="$(ex_rtl_date %Y-%m-%d-%H-%M-%S)"; BUILD_IS_PARENT=1;
-	BUILD_NFAIL="${BUILD_NFINI:=${BUILD_NSKIP:=0}}";
-	BUILD_PKGS_FAILED=""; BUILD_TIMES_SECS="$(ex_rtl_date %s)";
-	if [ "${ARG_FETCH_FORCE}" = "ipv4" ]; then
-		DEFAULT_GIT_ARGS="-4${DEFAULT_GIT_ARGS:+ ${DEFAULT_GIT_ARGS}}";
-		DEFAULT_WGET_ARGS="-4${DEFAULT_WGET_ARGS:+ ${DEFAULT_WGET_ARGS}}";
-	elif [ "${ARG_FETCH_FORCE}" = "ipv6" ]; then
-		DEFAULT_GIT_ARGS="-6${DEFAULT_GIT_ARGS:+ ${DEFAULT_GIT_ARGS}}";
-		DEFAULT_WGET_ARGS="-6${DEFAULT_WGET_ARGS:+ ${DEFAULT_WGET_ARGS}}";
-	fi;
+	rtl_log_set_vnfo_lvl "${ARG_VERBOSE:-0}";
+	case "${ARG_FETCH_FORCE}" in
+	ipv4)	DEFAULT_GIT_ARGS="$(rtl_lconcat "-4" "${DEFAULT_GIT_ARGS}")";
+		DEFAULT_WGET_ARGS="$(rtl_lconcat "-4" "${DEFAULT_GIT_ARGS}")"; ;;
+	ipv6)	DEFAULT_GIT_ARGS="$(rtl_lconcat "-6" "${DEFAULT_GIT_ARGS}")";
+		DEFAULT_WGET_ARGS="$(rtl_lconcat "-6" "${DEFAULT_GIT_ARGS}")"; ;;
+	esac;
 	return 0;
 };
 
-buildp_init_clean_prefix() {
-	if ex_rtl_lmatch "${ARG_CLEAN_BUILDS}" "prefix" ","; then
-		ex_rtl_log_msg info "-C prefix specified, cleaning prefix...";
-		for _pname in ${DEFAULT_CLEAR_PREFIX_PATHS}; do
-			ex_rtl_fileop rm "${PREFIX}/${_pname}";
-		done;
-	fi;
-	return 0;
+buildp_init_defaults() {
+	local _rc=0; _status="";
+
+	# Command-line arguments
+	ARCH="nt64"; BUILD="debug";
+	ARG_AS_NEEDED=0; ARG_CLEAN_BUILDS=""; ARG_DEBUG_MINIPIX=0; ARG_DIST="";
+	ARG_FETCH_FORCE=0; ARG_PARALLEL=1; ARG_RELAXED=0; ARG_RESTART=""; ARG_VERBOSE=0;
+
+	# Build parameters & state
+	BUILD_DLCACHEDIR="";BUILD_HNAME=""; BUILD_IS_PARENT=1; BUILD_GROUPS=""; BUILD_TARGET=""; BUILD_USER=""; BUILD_WORKDIR="";
+	MIDIPIX_BUILD_PWD=""; PREFIX=""; PREFIX_RPM="";
+
+	# Global defaults
+	DEFAULT_BUILD_CPUS=1;
+	DEFAULT_BUILD_LAST_FAILED_PKG_FNAME=""
+	DEFAULT_BUILD_LOG_FNAME="";
+	DEFAULT_BUILD_STATUS_IN_PROGRESS_FNAME="";
+	DEFAULT_BUILD_STEPS="";
+	DEFAULT_BUILD_VARS="";
+	DEFAULT_CLEAR_PREFIX_PATHS="";
+	DEFAULT_GIT_ARGS="";
+	DEFAULT_GITROOT_HEAD="";
+	DEFAULT_LOG_ENV_VARS="";
+	DEFAULT_TARGET="";
+	DEFAULT_WGET_ARGS="";
+
+	return "${_rc}";
 };
 
 buildp_init_env() {
-	local _rc=0 _vname="" _vname_val=""; _status="";
-	case "${ARG_PARALLEL}" in
-	auto)
-		if [ "${DEFAULT_BUILD_CPUS}" -gt 1 ]; then
-			ARG_PARALLEL=$((${DEFAULT_BUILD_CPUS}/2));
-		else
-			ARG_PARALLEL="${DEFAULT_BUILD_CPUS}";
-		fi; ;;
-	*[^0-9]*)
-		_rc=10; _status="Error: invalid jobs count \`${ARG_PARALLEL}'."; ;;
-	esac;
-	if [ "${_rc}" -eq 0 ]; then
-		ex_rtl_clean_env "${DEFAULT_CLEAR_ENV_VARS_EXCEPT}";
-		if ex_rtl_check_path_vars "${DEFAULT_CHECK_PATH_VARS}"; then
-			export PATH="${PREFIX}/bin${PATH:+:${PATH}}";
-		else
-			: $((_rc+=(11-1)));
-		fi;
+	local _cmd="" _cmds_missing="" _fname="" _rc=0; _status="";
+	if ! cd "$(dirname "${0}")" || ! umask 022; then
+		_rc=1; _status="Error: failed to setup environment";
+	else 	for _cmd in	\
+				awk bunzip2 cat chmod cmake cp date find flock g++	\
+				gcc git grep gunzip gzip hostname install kill		\
+				ln lzip make mkdir mkfifo mv paste patch perl		\
+				pgrep pkill printf readlink rm sed seq sha256sum	\
+				sort stat tail tar test touch tr wget xz zip; do
+			if ! which "${_cmd}" >/dev/null 2>&1; then
+				_cmds_missing="$(rtl_lconcat "${_cmds_missing}" "${_cmd}")";
+			fi;
+		done;
+		if [ -n "${_cmds_missing}" ]; then
+			_rc=1; _status="Error: missing prerequisite package(s): ${_cmds_missing}";
+		elif ! awk -V 2>/dev/null | grep -q "^GNU Awk "; then
+			_rc=1; _status="Error: awk(1) in \$PATH must be GNU Awk.";
+		elif ! sed --version 2>/dev/null | grep -q "^GNU sed "; then
+			_rc=1; _status="Error: sed(1) in \$PATH must be GNU sed.";
+		else for _fname in $(find subr -name *.subr); do
+			if ! . "${_fname}"; then
+				_rc=1; _status="Error: failed to source \`${_fname}'."; break;
+			fi;
+		done; fi;
 	fi;
 	return "${_rc}";
 };
 
-buildp_init_exec() {
-	_status=""
-	trap "buildp_ast abort" HUP INT TERM USR1 USR2; trap "buildp_ast exit" EXIT; umask 022;
-	return 0;
-};
-
 buildp_init_files() {
 	local _log_last_fname="" _log_last_ts="" _rc=0; _status=""
-	if ! ex_rtl_fileop mkdir "${BUILD_DLCACHEDIR}" "${BUILD_WORKDIR}"\
-	|| ex_rtl_lmatch "${ARG_DIST}" "rpm" ","\
-	&& ! ex_rtl_fileop mkdir "${PREFIX_RPM}"; then
-		_rc=13; _status="Error: cannot create build directories.";
+	if ! rtl_fileop mkdir "${BUILD_DLCACHEDIR}" "${BUILD_WORKDIR}"\
+	|| rtl_lmatch "${ARG_DIST}" "rpm" ","\
+	&& ! rtl_fileop mkdir "${PREFIX_RPM}"; then
+		_rc=1; _status="Error: cannot create build directories.";
 	elif [ -e "${DEFAULT_BUILD_STATUS_IN_PROGRESS_FNAME}" ]; then
-		_rc=14; _status="Error: another build targeting this architecture and build type is currently in progress.";
+		_rc=1; _status="Error: another build targeting this architecture and build type is currently in progress.";
+	elif ! rtl_clean_env "${DEFAULT_CLEAR_ENV_VARS_EXCEPT}"; then
+		_rc=1; _status="Error: failed to clean environment.";
+	elif ! rtl_check_path_vars "${DEFAULT_CHECK_PATH_VARS}"; then
+		_rc=1; _status="Error: one or more variable containing pathname(s) contains whitespace character(s).";
 	else
 		touch "${DEFAULT_BUILD_STATUS_IN_PROGRESS_FNAME}";
 		if [ -e "${DEFAULT_BUILD_LOG_FNAME}" ]; then
 			_log_last_ts="$(stat -c %Y "${DEFAULT_BUILD_LOG_FNAME}")";
 			_log_last_ts="$(awk 'BEGIN {printf(strftime("%Y-%m-%d-%H-%M-%S", '"${_log_last_ts}"'))}')";
 			_log_last_fname="${DEFAULT_BUILD_LOG_FNAME}.${_log_last_ts}";
-			ex_rtl_fileop mv "${DEFAULT_BUILD_LOG_FNAME}" "${_log_last_fname}";
-			ex_rtl_fileop ln_symbolic "${_log_last_fname}" "${DEFAULT_BUILD_LOG_LAST_FNAME}";
+			rtl_fileop mv "${DEFAULT_BUILD_LOG_FNAME}" "${_log_last_fname}";
+			rtl_fileop ln_symbolic "${_log_last_fname}" "${DEFAULT_BUILD_LOG_LAST_FNAME}";
+		fi;
+		rtl_fileop touch "${DEFAULT_BUILD_LOG_FNAME}";
+		if rtl_lmatch "${ARG_CLEAN_BUILDS}" "prefix" ","; then
+			rtl_log_msg info "-C prefix specified, cleaning prefix...";
+			for _pname in ${DEFAULT_CLEAR_PREFIX_PATHS}; do
+				if ! rtl_fileop rm "${PREFIX}/${_pname}"; then
+					_rc=1; _status="Error: failed to remove \`${PREFIX}/${_pname}'."; break;
+				fi;
+			done;
 		fi;
-		ex_rtl_fileop touch "${DEFAULT_BUILD_LOG_FNAME}";
+		export PATH="${PREFIX}/bin${PATH:+:${PATH}}";
 	fi;
 	return "${_rc}";
 };
 
 buildp_init_getopts() {
-	local _opt="" _shiftfl=0; _status="";
+	local _opt="" _rc=0 _shiftfl=0 OPTIND=0; _status="";
 	while [ "${#}" -gt 0 ]; do
 		case "${1}" in
 		--as-needed)	ARG_AS_NEEDED=1; _shiftfl=1; ;;
@@ -148,108 +169,75 @@ buildp_init_getopts() {
 	if [ "${_rc}" -eq 0 ]; then
 		while [ ${#} -gt 0 ]; do
 		case "${1}" in
-		*=*)		ex_rtl_set_var_unsafe "${1%%=*}" "${1#*=}"; ;;
-		[^a-zA-Z]*)	_rc=2; _status="Error: build group names must start with [a-zA-Z]."; ;;
-		*[^_a-zA-Z]*)	_rc=3; _status="Error: build group names must not contain [^_a-zA-Z]."; ;;
-		*)		BUILD_GROUPS="${BUILD_GROUPS:+${BUILD_GROUPS} }${1}"; ;;
+		*=*)		rtl_set_var_unsafe "${1%%=*}" "${1#*=}"; ;;
+		[^a-zA-Z]*)	_rc=1; _status="Error: build group names must start with [a-zA-Z]."; ;;
+		*[^_a-zA-Z]*)	_rc=1; _status="Error: build group names must not contain [^_a-zA-Z]."; ;;
+		*)		BUILD_GROUPS="$(rtl_lconcat "${BUILD_GROUPS}" "${1}")";
 		esac; shift; done;
 	fi;
 	return "${_rc}";
 };
 
-buildp_init_prereqs() {
-	local _cmd="" _cmds_missing="" _rc=0; _status="";
-	for _cmd in	\
-			awk bunzip2 cat chmod cmake cp date find flock g++	\
-			gcc git grep gunzip gzip hostname install kill		\
-			ln lzip make mkdir mkfifo mv paste patch perl		\
-			pgrep pkill printf readlink rm sed seq sha256sum	\
-			sort stat tail tar test touch tr wget xz zip; do
-		if ! which "${_cmd}" >/dev/null 2>&1; then
-			_cmds_missing="$(ex_rtl_lconcat "${_cmds_missing}" "${_cmd}")";
-		fi;
-	done;
-	if [ -n "${_cmds_missing}" ]; then
-		_rc=4; _status="Error: missing prerequisite package(s): ${_cmds_missing}";
-	elif ! awk -V 2>/dev/null | grep -q "^GNU Awk "; then
-		_rc=5; _status="Error: awk(1) in \$PATH must be GNU Awk.";
-	elif ! sed --version 2>/dev/null | grep -q "^GNU sed "; then
-		_rc=6; _status="Error: sed(1) in \$PATH must be GNU sed.";
-	fi;
-	return "${_rc}";
-};
-
-buildp_init_type() {
-	local _rc=0; _status="";
-	: ${ARCH:=nt64}; : ${BUILD:=debug};
-	if [ "${ARCH}" = nt32 ]; then
-		DEFAULT_TARGET="i686-nt32-midipix";
-	elif [ "${ARCH}" = nt64 ]; then
-		DEFAULT_TARGET="x86_64-nt64-midipix";
-	else
-		if [ "${BUILD}" != debug ]\
-		&& [ "${BUILD}" != release ]; then
-			_rc=7; _status="Error: unknown build type \`${BUILD}'.";
-		fi;
-		_rc=8; _status="Error: invalid architecture \`${ARCH}'.";
-	fi;
-	return "${_rc}";
-};
-
 buildp_init_vars() {
-	local _fname="" _rc=0; _status="";
-	if [ -z "${DEFAULT_BUILD_CPUS}" ]; then
-		if [ -e /proc/cpuinfo ]; then
+	local _default_build_groups="" _fname="" _rc=0 _target=""; _status="";
+	if ! rtl_lmatch "${ARCH}" "nt32 nt64"; then
+		_rc=1; _status="Error: invalid architecture \`${ARCH}'.";
+	elif ! rtl_lmatch "${BUILD}" "debug release"; then
+		_rc=1; _status="Error: unknown build type \`${BUILD}'.";
+	elif [ -n "${ARG_PARALLEL}" ] &&  [ "${ARG_PARALLEL}" != "auto" ]\
+	&&   ! rtl_isnumber "${ARG_PARALLEL}"; then
+		_rc=1; _status="Error: invalid jobs count \`${ARG_PARALLEL}'.";
+	else
+		case "${ARCH}" in
+		nt32)	DEFAULT_TARGET="i686-nt32-midipix"; ;;
+		nt64)	DEFAULT_TARGET="x86_64-nt64-midipix"; ;;
+		esac;
+		if [ -e "/proc/cpuinfo" ]; then
 			DEFAULT_BUILD_CPUS="$(awk '/^processor/{cpus++} END{print cpus}' /proc/cpuinfo)";
-		else
-			DEFAULT_BUILD_CPUS=1;
+			if [ "${ARG_PARALLEL}" = "auto" ]\
+			&& [ "${DEFAULT_BUILD_CPUS}" -gt 1 ]; then
+				ARG_PARALLEL=$((${DEFAULT_BUILD_CPUS}/2));
+			fi;
 		fi;
-	fi;
-	for _fname in	\
-			${HOME}/midipix_build.vars		\
-			${HOME}/.midipix_build.vars		\
-			../midipix_build.vars			\
-			./vars/env.vars; do
-		[ -e ${_fname} ] && . ${_fname};
-	done;
-	for _fname in $(find ./groups -name *.group | sort); do
-		. "${_fname}"; _fname="${_fname##*/}"; _fname="${_fname%.group}";
-		if [ "${_fname#[0-9][0-9][0-9].*}" != "${_fname}" ]\
-		&& [ "${_fname#*[1-9].*}" = "${_fname}" ]\
-		&& [ "${_fname}" != "999.invariants.group" ]; then
-			GROUPS_DEFAULT="${GROUPS_DEFAULT:+${GROUPS_DEFAULT} }${_fname#*.}";
+		rtl_fileop source_opt							\
+			"${HOME}/midipix_build.vars" "${HOME}/.midipix_build.vars"	\
+			../midipix_build.vars ./vars/env.vars;
+		if [ -z "${PREFIX}" ]; then
+			_rc=1; _status="Error: \${PREFIX} empty or unset.";
+		else
+			for _fname in $(find ./groups -name *.group | sort); do
+				rtl_fileop source_opt "${_fname}";
+				if [ -n "${BUILD_TARGET}" ]; then
+					_target="${BUILD_TARGET}"; unset BUILD_TARGET;
+				else
+					_fname="${_fname##*/}"; _fname="${_fname%.group}"; _target="${_fname#*.}";
+				fi;
+				_default_build_groups="$(rtl_lconcat "${_default_build_groups}" "${_target}")";
+			done;
+			if ! rtl_lmatch "${ARG_DIST}" "rpm" ","; then
+				_default_build_groups="$(rtl_lfilter "${_default_build_groups}" "host_deps_rpm")";
+			fi;
+			if [ -z "${BUILD_GROUPS}" ]; then
+				BUILD_GROUPS="${_default_build_groups}";
+			fi;
+			BUILD_GROUPS="$(rtl_lfilter "${BUILD_GROUPS}" "invariants")";
+			BUILD_GROUPS="$(rtl_lconcat "${BUILD_GROUPS}" "invariants")";
 		fi;
-	done;
-	if [ -z "${PREFIX}" ]; then
-		_rc=9; _status="Error: \${PREFIX} empty or unset.";
 	fi;
 	return "${_rc}";
 };
 
-build_fini() {
-	: $((BUILD_TIMES_SECS=$(ex_rtl_date %s)-${BUILD_TIMES_SECS}));
-	: $((BUILD_TIMES_HOURS=${BUILD_TIMES_SECS}/3600));
-	: $((BUILD_TIMES_MINUTES=(${BUILD_TIMES_SECS}%3600)/60));
-	: $((BUILD_TIMES_SECS=(${BUILD_TIMES_SECS}%3600)%60));
-	if [ -f "${DEFAULT_BUILD_STATUS_IN_PROGRESS_FNAME}" ]; then
-		ex_rtl_fileop rm ${DEFAULT_BUILD_STATUS_IN_PROGRESS_FNAME};
-	fi;
-};
-
 build_init() {
-	local _rc=0 _status="";
-	if ! buildp_init_exec		\
+	local _fname="" _rc=0 _status="";
+	if ! buildp_init_env		\
+	|| ! buildp_init_defaults	\
 	|| ! buildp_init_getopts "${@}"	\
-	|| ! buildp_init_prereqs	\
-	|| ! buildp_init_type		\
 	|| ! buildp_init_vars		\
-	|| ! buildp_init_env		\
 	|| ! buildp_init_args		\
-	|| ! buildp_init_files		\
-	|| ! buildp_init_clean_prefix; then
-		_rc="${?}"; ex_rtl_log_msg fail "${_status}"; exit "${_rc}";
+	|| ! buildp_init_files; then
+		_rc="${?}"; rtl_log_msg fail "${_status}"; exit "${_rc}";
 	elif [ -n "${_status}" ]; then
-		ex_rtl_log_msg info "${_status}"; exit 0;
+		rtl_log_msg info "${_status}"; exit 0;
 	else
 		return "${_rc}";
 	fi;
diff --git a/subr/ex_pkg.subr b/subr/ex_pkg.subr
new file mode 100644
index 00000000..fd2df524
--- /dev/null
+++ b/subr/ex_pkg.subr
@@ -0,0 +1,75 @@
+#
+# set +o errexit -o noglob is assumed.
+#
+
+#
+# ex_pkg_check_depends() - check single named package for unsatisfied dependencies
+# @_pkg_complete:	list of completed packages
+# @_pkg_name:		single package name
+# @_pkg_wait:		list of in-progress packages
+# @_restart_recursive:	optional flag specifiying either no dependency expansion (0,) dependency expansion (1,) dependency expansion and forcibly rebuild (2.)
+#
+# Return:		zero (0) given no outstanding dependencies, non-zero (>0) otherwise
+#
+ex_pkg_check_depends() {
+	local	_pkg_complete="${1}" _pkg_name="${2}" _pkg_wait="${3}" _restart_recursive="${4}"	\
+		_pkg_depends="" _pkg_name_depend="" _dependfl=0;
+	if _pkg_depends="$(rtl_lunfold_depends 'PKG_${_name}_DEPENDS' $(rtl_get_var_unsafe -u "PKG_"${_pkg_name}"_DEPENDS"))"\
+	&& [ -n "${_pkg_depends}" ]\
+	&& ! [ -n "${_restart}" ] || [ "${_restart_recursive:-0}" -ge 1 ]; then
+		for _pkg_name_depend in $(rtl_uniq ${_pkg_depends}); do
+			if ! rtl_lmatch "${_pkg_complete}" "${_pkg_name_depend}"\
+			|| rtl_lmatch "${_pkg_wait}" "${_pkg_name_depend}"; then
+				_dependfl=1; break;
+			fi;
+		done;
+	fi;
+	return "${_dependfl}";
+};
+
+#
+# ex_pkg_expand_packages() - expand build group name to list of packages ordered and filtered according to dependency and restart constraints
+# @_group_name:		build group name
+# @_restart:		optional comma-separated list of package names to rebuild
+# @_restart_recursive:	optional flag specifiying either no dependency expansion (0,) dependency expansion (1,) dependency expansion and forcibly rebuild (2.)
+#
+# Return:		zero (0) on success, non-zero (>0) on failure, ${EXP_PKG_COMPLETE}, ${EXP_PKG_DISABLED}, ${EXP_PKG_FINISHED}, and ${EXP_PKG_NAMES} set post-return.
+#
+ex_pkg_expand_packages() {
+	local	_group_name="${1}" _restart="${2}" _restart_recursive="${3}"	\
+		_pkg_name="" _pkg_names="" _restart_check=0;
+	EXP_PKG_COMPLETE=""; EXP_PKG_DISABLED=""; EXP_PKG_FINISHED=""; EXP_PKG_NAMES="";
+	if _pkg_names="$(rtl_get_var_unsafe -u "${_group_name}_PACKAGES")"\
+	&& [ -n "${_pkg_names}" ]; then
+		if [ -n "${_restart}" ] && ! rtl_lmatch "${_restart}" "ALL LAST"; then
+			_pkg_names="$(rtl_lsearch "${_pkg_names}" "${_restart}")";
+		fi;
+		if ! [ -n "${_restart}" ] || [ "${_restart_recursive:-0}" -ge 1 ]; then
+			_pkg_names="$(rtl_uniq $(rtl_lunfold_depends 'PKG_${_name}_DEPENDS' ${_pkg_names}))";
+		fi;
+		for _pkg_name in ${_pkg_names}; do
+			if [ "${_restart}" = "ALL" ]\
+			|| rtl_lmatch "${_restart}" "${_pkg_name}"; then
+				_restart_check=1;
+			else
+				_restart_check=0;
+			fi;
+			if [ -n "$(rtl_get_var_unsafe -u "PKG_${_pkg_name}_DISABLED")" ]; then
+				EXP_PKG_COMPLETE="$(rtl_lconcat "${EXP_PKG_COMPLETE}" "${_pkg_name}")";
+				EXP_PKG_DISABLED="$(rtl_lconcat "${EXP_PKG_DISABLED}" "${_pkg_name}")";
+				_pkg_names="$(rtl_lfilter "${_pkg_names}" "${_pkg_name}")";
+			elif ex_pkg_state_test "${_pkg_name}" finish\
+			&& [ "${_restart_check:-0}" -eq 0 ]\
+			&& [ "${_restart_recursive:-0}" -ne 2 ]\
+			&& [ "x$(rtl_get_var_unsafe -u "${_group_name}_FORCE")" != "x1" ]; then
+				EXP_PKG_COMPLETE="$(rtl_lconcat "${EXP_PKG_COMPLETE}" "${_pkg_name}")";
+				EXP_PKG_FINISHED="$(rtl_lconcat "${EXP_PKG_FINISHED}" "${_pkg_name}")";
+				_pkg_names="$(rtl_lfilter "${_pkg_names}" "${_pkg_name}")";
+			fi;
+		done;
+		EXP_PKG_NAMES="${_pkg_names}";
+	fi;
+	return 0;
+};
+
+# vim:filetype=sh textwidth=0
diff --git a/subr/ex_pkg_dispatch.subr b/subr/ex_pkg_dispatch.subr
index 2d34a900..bd152f28 100644
--- a/subr/ex_pkg_dispatch.subr
+++ b/subr/ex_pkg_dispatch.subr
@@ -3,49 +3,106 @@
 #
 
 #
-# exp_pkg_check_depends() - check single named package for unsatisfied dependencies
-# @_pkg_complete:	list of completed packages
-# @_pkg_name:		single package name
-# @_pkg_wait:		list of in-progress packages
-# @_restart_recursive:	optional flag specifiying either no dependency expansion (0,) dependency expansion (1,) dependency expansion and forcibly rebuild (2.)
-#
-# Return:		zero (0) given no outstanding dependencies, non-zero (>0) otherwise
-#
-exp_pkg_check_depends() {
-	local	_pkg_complete="${1}" _pkg_name="${2}" _pkg_wait="${3}" _restart_recursive="${4}"	\
-		_pkg_depends="" _pkg_name_depend="" _dependfl=0;
-	if _pkg_depends="$(ex_rtl_lunfold_depends 'PKG_${_name}_DEPENDS' $(ex_rtl_get_var_unsafe -u "PKG_"${_pkg_name}"_DEPENDS"))"\
-	&& [ -n "${_pkg_depends}" ]\
-	&& ! [ -n "${_restart}" ] || [ "${_restart_recursive:-0}" -ge 1 ]; then
-		for _pkg_name_depend in $(ex_rtl_uniq ${_pkg_depends}); do
-			if ! ex_rtl_lmatch "${_pkg_complete}" "${_pkg_name_depend}"\
-			|| ex_rtl_lmatch "${_pkg_wait}" "${_pkg_name_depend}"; then
-				_dependfl=1; break;
+# exp_pkg_dispatch_complete() - XXX
+# @_dispatch_fn:	top-level dispatch function name
+# @_group_names:	build group name(s)
+# @_pkg_disabled:	list of disabled packages
+# @_pkg_finished:	list of finished packages
+#
+# Return:		zero (0) on success, non-zero (>0) on failure.
+#
+exp_pkg_dispatch_complete() {
+	local _dispatch_fn="${1}" _group_name="${2}" _pkg_disabled="${3}" _pkg_finished="${4}" _pkg_name="";
+	for _pkg_name in ${_pkg_disabled}; do
+		"${_dispatch_fn}" disabled_pkg "${_group_name}" "${_pkg_name}";
+	done;
+	for _pkg_name in ${_pkg_finished}; do
+		"${_dispatch_fn}" skipped_pkg "${_group_name}" "${_pkg_name}";
+	done;
+};
+
+#
+# exp_pkg_dispatch_group() - dispatch a single build group
+# @_build_steps_default:	list of default build steps
+# @_build_vars_default:		list of default build variables
+# @_dispatch_fn:		top-level dispatch function name
+# @_group_name:			build group name
+# @_njobs_max:			maximum count of simultaneous jobs
+# @_pipe_path:			pathname to build FIFO
+# @_restart_at:			optional comma-separated list of build steps at which to rebuild or ALL
+# @_restart_recursive:		optional flag specifiying either no dependency expansion (0,) dependency expansion (1,) dependency expansion and forcibly rebuild (2.)
+# @_workdir:			pathname to build-specific temporary directory
+#
+# Return:			zero (0) on success, non-zero (>0) on failure.
+#
+exp_pkg_dispatch_group() {
+	local	_build_steps_default="${1}" _build_vars_default="${2}" _dispatch_fn="${3}"	\
+		_group_name="${4}" _njobs_max="${5}" _pipe_path="${6}" _restart_at="${7}"	\
+		_restart_recursive="${8}" _workdir="${9}" _pipe_msg="" _pkg_name="" _rc=0;
+	rtl_fileop mkfifo "${_pipe_path}";
+	while true; do
+		while [ "${EXP_PKG_DISPATCH_NJOBS:-0}" -gt 0 ] && read _pipe_msg; do
+		case "${_pipe_msg%% *}" in
+		done)	: $((EXP_PKG_DISPATCH_NJOBS-=1)); _pkg_name="${_pipe_msg#done * }";
+			"${_dispatch_fn}" finish_pkg ${_pipe_msg#done };
+			EXP_PKG_COMPLETE="$(rtl_lconcat "${EXP_PKG_COMPLETE}" "${_pkg_name}")";
+			EXP_PKG_NAMES="$(rtl_lfilter "${EXP_PKG_NAMES}" "${_pkg_name}")";
+			EXP_PKG_DISPATCH_WAIT="$(rtl_lfilter "${EXP_PKG_DISPATCH_WAIT}" "${_pkg_name}")";
+			if [ -n "${EXP_PKG_NAMES}" ] && [ "${_rc}" -eq 0 ]; then
+				if [ "${EXP_PKG_DISPATCH_NJOBS}" -ne "${_njobs_max}" ]; then
+					exp_pkg_dispatch_packages "${_build_steps_default}"	\
+						"${_build_vars_default}" "${_dispatch_fn}"	\
+						"${_group_name}" "${_njobs_max}"		\
+						"${_pipe_path}" "${EXP_PKG_COMPLETE}"		\
+						"${_restart_at}" "${_restart_recursive}" "${_workdir}";
+				fi;
+			elif [ "${EXP_PKG_DISPATCH_NJOBS:-0}" -eq 0 ]; then
+				break;
+			fi; ;;
+		fail)	: $((EXP_PKG_DISPATCH_NJOBS-=1)); _rc=1;
+			"${_dispatch_fn}" fail_pkg ${_pipe_msg#fail }; ;;
+		step)	"${_dispatch_fn}" step_pkg ${_pipe_msg#step }; ;;
+		esac; done <>"${_pipe_path}";
+		if [ -n "${EXP_PKG_NAMES}" ] && [ "${_rc}" -eq 0 ]; then
+			if [ "${EXP_PKG_DISPATCH_NJOBS}" -ne "${_njobs_max}" ]; then
+				exp_pkg_dispatch_packages "${_build_steps_default}"		\
+					"${_build_vars_default}" "${_dispatch_fn}"		\
+					"${_group_name}" "${_njobs_max}" "${_pipe_path}"	\
+					"${EXP_PKG_COMPLETE}" "${_restart_at}"			\
+					"${_restart_recursive}" "${_workdir}";
 			fi;
-		done;
-	fi;
-	return "${_dependfl}";
+		elif [ "${EXP_PKG_DISPATCH_NJOBS:-0}" -eq 0 ]; then
+			break;
+		fi;
+	done;
+	rtl_fileop rm "${_pipe_path}";
+	return "${_rc}";
 };
 
 #
 # exp_pkg_dispatch_package() - dispatch single named packages
-# @_dispatch_fn:	top-level dispatch function name
-# @_group_name:		build group name
-# @_pkg_name:		single package name
-# @_restart_at:		optional comma-separated list of build steps at which to rebuild or ALL
+# @_build_steps_default:	list of default build steps
+# @_build_vars_default:		list of default build variables
+# @_dispatch_fn:		top-level dispatch function name
+# @_group_name:			build group name
+# @_pkg_name:			single package name
+# @_restart_at:			optional comma-separated list of build steps at which to rebuild or ALL
+# @_workdir:			pathname to build-specific temporary directory
 #
-# Return:		zero (0) on success, non-zero (>0) on failure, ${NJOBS}, ${PKG_COUNT}, ${PKG_NAMES}, and ${PKG_WAIT} may be mutated post-return.
+# Return:			zero (0) on success, non-zero (>0) on failure, ${EXP_PKG_DISPATCH_NJOBS}, ${EXP_PKG_DISPATCH_COUNT}, ${EXP_PKG_NAMES}, and ${EXP_PKG_DISPATCH_WAIT} may be mutated post-return.
 #
 exp_pkg_dispatch_package() {
-	local _dispatch_fn="${1}" _group_name="${2}" _pkg_name="${3}" _restart_at="${4}";
-	if "${_dispatch_fn}" start_pkg "${_group_name}" "${_pkg_name}" "$((${PKG_COUNT}+1))" "${PKG_COUNT_MAX}"; then
-		: $((NJOBS+=1)); : $((PKG_COUNT+=1)); PKG_WAIT="$(ex_rtl_lconcat "${PKG_WAIT}" "${_pkg_name}")";
+	local	_build_steps_default="${1}" _build_vars_default="${2}" _dispatch_fn="${3}"	\
+		_group_name="${4}" _pkg_name="${5}" _restart_at="${6}" _workdir="${7}";
+	if "${_dispatch_fn}" start_pkg "${_group_name}" "${_pkg_name}" "$((${EXP_PKG_DISPATCH_COUNT}+1))" "${EXP_PKG_DISPATCH_COUNT_MAX}"; then
+		: $((EXP_PKG_DISPATCH_NJOBS+=1)); : $((EXP_PKG_DISPATCH_COUNT+=1)); EXP_PKG_DISPATCH_WAIT="$(rtl_lconcat "${EXP_PKG_DISPATCH_WAIT}" "${_pkg_name}")";
 		(set +o errexit -o noglob; BUILD_IS_PARENT=0;
-		if ex_pkg_env "${_group_name}" "${_pkg_name}" "${_restart_at}"; then
+		if ex_pkg_env "${_build_steps_default}" "${_build_vars_default}"	\
+				"${_group_name}" "${_pkg_name}" "${_restart_at}" "${_workdir}"; then
 			ex_pkg_exec "${_dispatch_fn}" "${_group_name}" "${_pkg_name}" "${_restart_at}";
 		else
 			return "${?}";
-		fi;) 1>"${BUILD_WORKDIR}/${_pkg_name}_stderrout.log" 2>&1 3>"${_pipe_path}" &
+		fi;) 1>"${_workdir}/${_pkg_name}_stderrout.log" 2>&1 3>"${_pipe_path}" &
 	else
 		return "${?}";
 	fi;
@@ -53,123 +110,96 @@ exp_pkg_dispatch_package() {
 
 #
 # exp_pkg_dispatch_packages() - dispatch set of packages
-# @_dispatch_fn:	top-level dispatch function name
-# @_group_name:		build group name
-# @_njobs_max:		maximum count of simultaneous jobs
-# @_pipe_path:		pathname to parent-child process FIFO
-# @_pkg_complete:	list of completed packages
-# @_restart_at:		optional comma-separated list of build steps at which to rebuild or ALL
-# @_restart_recursive:	optional flag specifiying either no dependency expansion (0,) dependency expansion (1,) dependency expansion and forcibly rebuild (2.)
-#
-# Return:		zero (0) on success, non-zero (>0) on failure, ${NJOBS}, ${PKG_COUNT}, ${PKG_NAMES}, and ${PKG_WAIT} may be mutated post-return.
+# @_build_steps_default:	list of default build steps
+# @_build_vars_default:		list of default build variables
+# @_dispatch_fn:		top-level dispatch function name
+# @_group_name:			build group name
+# @_njobs_max:			maximum count of simultaneous jobs
+# @_pipe_path:			pathname to parent-child process FIFO
+# @_pkg_complete:		list of completed packages
+# @_restart_at:			optional comma-separated list of build steps at which to rebuild or ALL
+# @_restart_recursive:		optional flag specifiying either no dependency expansion (0,) dependency expansion (1,) dependency expansion and forcibly rebuild (2.)
+# @_workdir:			pathname to build-specific temporary directory
+#
+# Return:			zero (0) on success, non-zero (>0) on failure, ${EXP_PKG_DISPATCH_NJOBS}, ${EXP_PKG_DISPATCH_COUNT}, ${EXP_PKG_NAMES}, and ${EXP_PKG_DISPATCH_WAIT} may be mutated post-return.
 #
 exp_pkg_dispatch_packages() {
-	local	_dispatch_fn="${1}" _group_name="${2}" _njobs_max="${3}" _pipe_path="${4}"		\
-		_pkg_complete="${5}" _restart_at="${6}" _restart_recursive="${7}"			\
+	local	_build_steps_default="${1}" _build_vars_default="${2}" _dispatch_fn="${3}"		\
+		_group_name="${4}" _njobs_max="${5}" _pipe_path="${6}" _pkg_complete="${7}"		\
+		_restart_at="${8}" _restart_recursive="${9}" _workdir="${10}"				\
 		_njob=0 _pkg_depends="" _pkg_name="";
-	for _njob in $(seq 1 $((${_njobs_max}-${NJOBS}))); do
-		for _pkg_name in ${PKG_NAMES}; do
-			if ! ex_rtl_lmatch "${_pkg_complete}" "${_pkg_name}"\
-			&& ! ex_rtl_lmatch "${PKG_WAIT}" "${_pkg_name}"\
-			&& exp_pkg_check_depends "${_pkg_complete}" "${_pkg_name}" "${PKG_WAIT}" "${_restart_recursive}"; then
-				exp_pkg_dispatch_package "${_dispatch_fn}" "${_group_name}" "${_pkg_name}" "${_restart_at}"; break;
+	for _njob in $(seq 1 $((${_njobs_max}-${EXP_PKG_DISPATCH_NJOBS}))); do
+		for _pkg_name in ${EXP_PKG_NAMES}; do
+			if ! rtl_lmatch "${_pkg_complete}" "${_pkg_name}"\
+			&& ! rtl_lmatch "${EXP_PKG_DISPATCH_WAIT}" "${_pkg_name}"\
+			&& ex_pkg_check_depends "${_pkg_complete}" "${_pkg_name}" "${EXP_PKG_DISPATCH_WAIT}" "${_restart_recursive}"; then
+				exp_pkg_dispatch_package "${_build_steps_default}"			\
+					"${_build_vars_default}" "${_dispatch_fn}"			\
+					"${_group_name}" "${_pkg_name}" "${_restart_at}"		\
+					"${_workdir}"; break;
 			fi;
 		done;
 	done;
 };
 
 #
-# exp_pkg_expand_packages() - expand build group name to list of packages ordered and filtered according to dependency and restart constraints
-# @_group_name:		build group name
-# @_restart:		optional comma-separated list of package names to rebuild
-# @_restart_recursive:	optional flag specifiying either no dependency expansion (0,) dependency expansion (1,) dependency expansion and forcibly rebuild (2.)
+# ex_pkg_dispatch() - dispatch a set of build group
+# @_build_steps_default:	list of default build steps
+# @_build_vars_default:		list of default build variables
+# @_dispatch_fn:		top-level dispatch function name
+# @_group_names:		build group name(s)
+# @_njobs_max:			maximum count of simultaneous jobs
+# @_pipe_path:			pathname to build FIFO
+# @_restart:			optional comma-separated list of package names to rebuild
+# @_restart_at:			optional comma-separated list of build steps at which to rebuild or ALL
+# @_restart_recursive:		optional flag specifiying either no dependency expansion (0,) dependency expansion (1,) dependency expansion and forcibly rebuild (2.)
+# @_workdir:			pathname to build-specific temporary directory
 #
-# Return:		zero (0) on success, non-zero (>0) on failure, ${EX_PKG_NAMES} and ${PKG_COMPLETE} set post-return.
+# Return:			zero (0) on success, non-zero (>0) on failure, ${EX_PKG_DISPATCH_UNKNOWN} mutated post-return.
 #
-exp_pkg_expand_packages() {
-	local _group_name="${1}" _restart="${2}" _restart_recursive="${3}" _pkg_name="" _pkg_names="";
-	if _pkg_names="$(ex_rtl_get_var_unsafe -u "${_group_name}_PACKAGES")"\
-	&& [ -n "${_pkg_names}" ]; then
-		if [ -n "${_restart}" ] && ! ex_rtl_lmatch "${_restart}" "ALL LAST"; then
-			_pkg_names="$(ex_rtl_lsearch "${_pkg_names}" "${_restart}")";
-		fi;
-		if ! [ -n "${_restart}" ] || [ "${_restart_recursive:-0}" -ge 1 ]; then
-			_pkg_names="$(ex_rtl_uniq $(ex_rtl_lunfold_depends 'PKG_${_name}_DEPENDS' ${_pkg_names}))";
+ex_pkg_dispatch() {
+	local	_build_steps_default="${1}" _build_vars_default="${2}" _dispatch_fn="${3}"		\
+		_group_names="${4}" _njobs_max="${5}" _pipe_path="${6}" _restart="${7}"			\
+		_restart_at="${8}" _restart_recursive="${9}" _workdir="${10}"				\
+		_pkg_name="" _pkg_names="" _rc=0							\
+		EXP_PKG_COMPLETE EXP_PKG_DISABLED EXP_PKG_FINISHED EXP_PKG_DISPATCH_COUNT		\
+		EXP_PKG_DISPATCH_COUNT_MAX EXP_PKG_DISPATCH_NJOBS EXP_PKG_NAMES EXP_PKG_DISPATCH_WAIT;
+	EX_PKG_DISPATCH_UNKNOWN="";
+	for _group_name in ${_group_names}; do
+		EXP_PKG_COMPLETE="" EXP_PKG_DISABLED="" EXP_PKG_FINISHED="";
+		EXP_PKG_DISPATCH_COUNT=0 EXP_PKG_DISPATCH_COUNT_MAX=0 EXP_PKG_DISPATCH_NJOBS=0;
+		EXP_PKG_NAMES="" EXP_PKG_DISPATCH_WAIT="";
+		if "${_dispatch_fn}" start_group "${_group_name}" ""; then
+			if rtl_fileop mkdir "${_workdir}"\
+			&& rtl_log_msg vnfo "Resolving \`${_group_name}' dependencies..."\
+			&& ex_pkg_expand_packages "${_group_name}" "${_restart}" "${_restart_recursive}"\
+			&& exp_pkg_dispatch_complete "${_dispatch_fn}" "${_group_name}" "${EXP_PKG_DISABLED}" "${EXP_PKG_FINISHED}"\
+			&& rtl_log_msg vnfo "Resolved \`${_group_name}' dependencies."\
+			&& EXP_PKG_DISPATCH_COUNT_MAX="$(rtl_llength "${EXP_PKG_NAMES}")"\
+			&& [ "${EXP_PKG_DISPATCH_COUNT_MAX}" -gt 0 ]; then
+				_pkg_names="$(rtl_lconcat "${_pkg_names}" "${EXP_PKG_NAMES}")";
+				exp_pkg_dispatch_group "${_build_steps_default}"			\
+					"${_build_vars_default}" "${_dispatch_fn}" "${_group_name}"	\
+					"${_njobs_max}" "${_pipe_path}" "${_restart_at}"		\
+					"${_restart_recursive}" "${_workdir}"; _rc="${?}";
+			fi;
+			"${_dispatch_fn}" finish_group "${_group_name}" "";
+			if [ "${_rc}" -ne 0 ]; then
+				break;
+			fi;
 		fi;
-		for _pkg_name in ${_pkg_names}; do
-			if [ -n "$(ex_rtl_get_var_unsafe -u "PKG_${_pkg_name}_DISABLED")" ]; then
-				PKG_COMPLETE="$(ex_rtl_lconcat "${PKG_COMPLETE}" "${_pkg_name}")";
-				_pkg_names="$(ex_rtl_lfilter "${_pkg_names}" "${_pkg_name}")";
-				"${_dispatch_fn}" disabled_pkg "${_group_name}" "${_pkg_name}";
-			elif ex_pkg_state_test "${_pkg_name}" finish\
-			&& ! ex_rtl_lmatch "${_restart}" "${_pkg_name}"\
-			&& [ "${_restart_recursive:-0}" -ne 2 ]; then
-				PKG_COMPLETE="$(ex_rtl_lconcat "${PKG_COMPLETE}" "${_pkg_name}")";
-				_pkg_names="$(ex_rtl_lfilter "${_pkg_names}" "${_pkg_name}")";
-				"${_dispatch_fn}" skipped_pkg "${_group_name}" "${_pkg_name}";
+	done;
+	if ! rtl_lmatch "${_restart}" "ALL LAST"; then
+		for _pkg_name in ${_restart}; do
+			if ! rtl_lmatch "${_pkg_names}" "${_restart}"; then
+				EX_PKG_DISPATCH_UNKNOWN="$(rtl_lconcat "${EX_PKG_DISPATCH_UNKNOWN}" "${_pkg_name}")";
 			fi;
 		done;
-		EX_PKG_NAMES="${_pkg_names}"; return 0;
 	fi;
-};
-
-#
-# ex_pkg_dispatch() - dispatch a single build group
-# @_dispatch_fn:	top-level dispatch function name
-# @_group_name:		build group name
-# @_njobs_max:		maximum count of simultaneous jobs
-# @_restart:		optional comma-separated list of package names to rebuild
-# @_restart_at:		optional comma-separated list of build steps at which to rebuild or ALL
-# @_restart_recursive:	optional flag specifiying either no dependency expansion (0,) dependency expansion (1,) dependency expansion and forcibly rebuild (2.)
-#
-# Return:		zero (0) on success, non-zero (>0) on failure, ${EX_PKG_NAMES} set post-return.
-#
-ex_pkg_dispatch() {
-	local	_dispatch_fn="${1}" _group_name="${2}" _njobs_max="${3}" _restart="${4}" _restart_at="${5}"			\
-		_restart_recursive="${6}" _pipe_msg="" _pipe_path="${BUILD_WORKDIR}/build.fifo" _pkg_name=""			\
-		_script_rc=0 NJOBS=0 PKG_COMPLETE="" PKG_COUNT=0 PKG_COUNT_MAX=0 PKG_NAMES="" PKG_WAIT=""; EX_PKG_NAMES="";
-	if "${_dispatch_fn}" start_group "${_group_name}" ""; then
-		if ex_rtl_fileop mkdir "${BUILD_WORKDIR}"\
-		&& ex_rtl_log_msg vnfo "Resolving \`${_group_name}' dependencies..."\
-		&& exp_pkg_expand_packages "${_group_name}" "${_restart}" "${_restart_recursive}"\
-		&& ex_rtl_log_msg vnfo "Resolved \`${_group_name}' dependencies."\
-		&& PKG_COUNT_MAX="$(ex_rtl_llength "${EX_PKG_NAMES}")"\
-		&& [ "${PKG_COUNT_MAX}" -gt 0 ]; then
-			PKG_NAMES="${EX_PKG_NAMES}"; ex_rtl_fileop mkfifo "${_pipe_path}";
-			while true; do
-				while [ "${NJOBS:-0}" -gt 0 ] && read _pipe_msg; do
-				case "${_pipe_msg%% *}" in
-				done)	: $((NJOBS-=1)); _pkg_name="${_pipe_msg#done * }";
-					"${_dispatch_fn}" finish_pkg ${_pipe_msg#done };
-					PKG_COMPLETE="$(ex_rtl_lconcat "${PKG_COMPLETE}" "${_pkg_name}")";
-					PKG_NAMES="$(ex_rtl_lfilter "${PKG_NAMES}" "${_pkg_name}")";
-					PKG_WAIT="$(ex_rtl_lfilter "${PKG_WAIT}" "${_pkg_name}")";
-					if [ -n "${PKG_NAMES}" ] && [ "${_script_rc}" -eq 0 ]; then
-						if [ "${NJOBS}" -ne "${_njobs_max}" ]; then
-							exp_pkg_dispatch_packages "${_dispatch_fn}" "${_group_name}" "${_njobs_max}"	\
-								"${_pipe_path}" "${PKG_COMPLETE}" "${_restart_at}" "${_restart_recursive}";
-						fi;
-					elif [ "${NJOBS:-0}" -eq 0 ]; then
-						break;
-					fi; ;;
-				fail)	: $((NJOBS-=1)); _script_rc=1;
-					"${_dispatch_fn}" fail_pkg ${_pipe_msg#fail }; ;;
-				step)	"${_dispatch_fn}" step_pkg ${_pipe_msg#step }; ;;
-				esac; done <>"${_pipe_path}";
-				if [ -n "${PKG_NAMES}" ] && [ "${_script_rc}" -eq 0 ]; then
-					if [ "${NJOBS}" -ne "${_njobs_max}" ]; then
-						exp_pkg_dispatch_packages "${_dispatch_fn}" "${_group_name}" "${_njobs_max}"	\
-							"${_pipe_path}" "${PKG_COMPLETE}" "${_restart_at}" "${_restart_recursive}";
-					fi;
-				elif [ "${NJOBS:-0}" -eq 0 ]; then
-					break;
-				fi;
-			done;
-			ex_rtl_fileop rm "${_pipe_path}";
-		fi;
-		"${_dispatch_fn}" finish_group "${_group_name}" "";
+	if [ -n "${EX_PKG_DISPATCH_UNKNOWN}" ]; then
+		_rc=1;
 	fi;
-	return "${_script_rc}";
+	return "${_rc}";
 };
 
 # vim:filetype=sh textwidth=0
diff --git a/subr/ex_pkg_env.subr b/subr/ex_pkg_env.subr
index e92f5e45..7f58d3d0 100644
--- a/subr/ex_pkg_env.subr
+++ b/subr/ex_pkg_env.subr
@@ -4,17 +4,19 @@
 
 #
 # exp_pkg_env_defaults() - set package variable defaults for single named package
-# @_pkg_name:		single package name
+# @_build_steps_default:	list of default build steps
+# @_pkg_name:			single package name
+# @_workdir:			pathname to build-specific temporary directory
 #
 # Return:		zero (0) on success, non-zero (>0) on failure
 #
 exp_pkg_env_defaults() {
-	local _pkg_name="${1}";
+	local _build_steps_default="${1}" _pkg_name="${2}" _workdir="${3}";
 	: ${PKG_NAME:="${_pkg_name}"};
 	: ${MIDIPIX_BUILD_PWD:="$(pwd)"};
-	: ${PKG_BASE_DIR:="${BUILD_WORKDIR}/${_pkg_name}-${PKG_BUILD_TYPE}-${PKG_TARGET}"};
+	: ${PKG_BASE_DIR:="${_workdir}/${_pkg_name}-${PKG_BUILD_TYPE}-${PKG_TARGET}"};
 	: ${PKG_FNAME:="${PKG_URL##*/}"};
-	: ${PKG_BUILD_STEPS:="$(ex_rtl_lfilter "${DEFAULT_BUILD_STEPS}" "${PKG_BUILD_STEPS_DISABLE}")"};
+	: ${PKG_BUILD_STEPS:="$(rtl_lfilter "${_build_steps_default}" "${PKG_BUILD_STEPS_DISABLE}")"};
 	if [ -z "${PKG_SUBDIR}" ]; then
 		if [ -n "${PKG_URLS_GIT}" ]; then
 			PKG_SUBDIR="${PKG_URLS_GIT%%=*}";
@@ -36,6 +38,7 @@ exp_pkg_env_defaults() {
 
 #
 # exp_pkg_env_set() - set package variables for single named package
+# @_build_vars_default:	list of default build variables
 # @_group_name:		build group name
 # @_pkg_name:		single package name
 #
@@ -47,40 +50,44 @@ exp_pkg_env_defaults() {
 # Return:		zero (0) on success, non-zero (>0) on failure
 #
 exp_pkg_env_set() {
-	local _group_name="${1}" _pkg_name="${2}" _var_prefixes="" _vars_set="" _vname="";
-	ex_rtl_set_vars _vars_set BUILD_TYPE "DEFAULT ${_group_name} PKG_${_pkg_name}";
-	ex_rtl_set_vars _vars_set INHERIT_FROM "PKG_${_pkg_name}";
-	_var_prefixes="$(ex_rtl_toupper "DEFAULT DEFAULT_${PKG_BUILD_TYPE} ${_group_name}")";
-	for _vname in $(ex_rtl_lfilter "${DEFAULT_BUILD_VARS}" BUILD_TYPE); do
+	local _build_vars_default="${1}" _group_name="${2}" _pkg_name="${3}" _var_prefixes="" _vars_set="" _vname="";
+	rtl_set_vars _vars_set BUILD_TYPE "DEFAULT ${_group_name} PKG_${_pkg_name}";
+	rtl_set_vars _vars_set INHERIT_FROM "PKG_${_pkg_name}";
+	_var_prefixes="$(rtl_toupper "DEFAULT DEFAULT_${PKG_BUILD_TYPE} ${_group_name}")";
+	for _vname in $(rtl_lfilter "${_build_vars_default}" BUILD_TYPE); do
 		if [ -n "${PKG_INHERIT_FROM}" ]; then
-			ex_rtl_set_vars _vars_set "${_vname}"	\
-				"$(ex_rtl_lconcat "${_var_prefixes}" "$(ex_rtl_toupper "PKG_${PKG_INHERIT_FROM} PKG_${_pkg_name}")")"
+			rtl_set_vars _vars_set "${_vname}"	\
+				"$(rtl_lconcat "${_var_prefixes}" "$(rtl_toupper "PKG_${PKG_INHERIT_FROM} PKG_${_pkg_name}")")"
 		else
-			ex_rtl_set_vars _vars_set "${_vname}"	\
-				"$(ex_rtl_lconcat "${_var_prefixes}" "$(ex_rtl_toupper "PKG_${_pkg_name}")")";
+			rtl_set_vars _vars_set "${_vname}"	\
+				"$(rtl_lconcat "${_var_prefixes}" "$(rtl_toupper "PKG_${_pkg_name}")")";
 		fi;
 	done;
-	ex_rtl_push_IFS :; for _vname in ${PKG_ENV_VARS_EXTRA}; do
+	rtl_push_IFS :; for _vname in ${PKG_ENV_VARS_EXTRA}; do
 		export "${_vname}";
-	done; ex_rtl_pop_IFS;
-	ex_rtl_unset_vars $(ex_rtl_lfilter			\
+	done; rtl_pop_IFS;
+	rtl_unset_vars $(rtl_lfilter			\
 		"$(set | awk -F= '/^PKG_/{print $1}' | sort)"	\
 		"${_vars_set}");
 };
 
 #
 # ex_pkg_env() - set package variables for single named package
-# @_group_name:		build group name
-# @_pkg_name:		single package name
-# @_restart_at:		optional comma-separated list of build steps at which to rebuild or ALL
+# @_build_steps_default:	list of default build steps
+# @_build_vars_default:		list of default build variables
+# @_group_name:			build group name
+# @_pkg_name:			single package name
+# @_restart_at:			optional comma-separated list of build steps at which to rebuild or ALL
+# @_workdir:			pathname to build-specific temporary directory
 #
 # Return:		zero (0) on success, non-zero (>0) on failure
 #
 ex_pkg_env() {
-	local _group_name="${1}" _pkg_name="${2}" _restart_at="${3}" _vname="";
-	ex_rtl_fileop source_opt "vars/${_pkg_name}.vars";
-	if ! exp_pkg_env_set "${_group_name}" "${_pkg_name}"\
-	|| ! exp_pkg_env_defaults "${_pkg_name}"; then
+	local	_build_steps_default="${1}" _build_vars_default="${2}" _group_name="${3}"	\
+		_pkg_name="${4}" _restart_at="${5}" _workdir="${6}" _vname="";
+	rtl_fileop source_opt "vars/${_pkg_name}.vars";
+	if ! exp_pkg_env_set "${_build_vars_default}" "${_group_name}" "${_pkg_name}"\
+	|| ! exp_pkg_env_defaults "${_build_steps_default}" "${_pkg_name}" "${_workdir}"; then
 		return "${?}";
 	fi;
 };
@@ -94,7 +101,7 @@ ex_pkg_env() {
 # Return:		zero (0) on success, non-zero (>0) on failure
 #
 ex_pkg_state_set() {
-	ex_rtl_state_set "${BUILD_WORKDIR}" "${@}";
+	rtl_state_set "${_workdir}" "${@}";
 };
 
 #
@@ -107,7 +114,7 @@ ex_pkg_state_set() {
 # Return:		zero (0) on success, non-zero (>0) on failure
 #
 ex_pkg_state_test() {
-	ex_rtl_state_test "${BUILD_WORKDIR}" "${@}";
+	rtl_state_test "${_workdir}" "${@}";
 };
 
 # vim:filetype=sh
diff --git a/subr/ex_pkg_exec.subr b/subr/ex_pkg_exec.subr
index 2d14a018..0a40cfcf 100644
--- a/subr/ex_pkg_exec.subr
+++ b/subr/ex_pkg_exec.subr
@@ -15,21 +15,21 @@ exp_pkg_exec_pre() {
 	if [ -z "${PKG_URL}" ]\
 	&& [ -z "${PKG_URLS_GIT}" ]\
 	&& [ -z "${PKG_VERSION}" ]\
-	&& ! ex_rtl_test_cmd "pkg_${_pkg_name}_all"; then
-		"${_dispatch_fn}" exec_missing "${_group_name}" "${_pkg_name}";
+	&& ! rtl_test_cmd "pkg_${_pkg_name}_all"; then
+		"${_dispatch_fn}" missing_pkg "${_group_name}" "${_pkg_name}";
 		return 1;
 	elif ! ex_pkg_state_test "${_pkg_name}" "start" "${_restart_at}"; then
 		if [ "${PKG_NO_CLEAN_BASE_DIR:-0}" -eq 0 ]\
-		&& ! ex_rtl_fileop rm "${PKG_BASE_DIR}" "${PKG_BUILD_DIR}" "${PKG_DESTDIR}"\
-		|| ! ex_rtl_fileop mkdir "${PKG_BASE_DIR}"; then
+		&& ! rtl_fileop rm "${PKG_BASE_DIR}" "${PKG_BUILD_DIR}" "${PKG_DESTDIR}"\
+		|| ! rtl_fileop mkdir "${PKG_BASE_DIR}"; then
 			return "${?}";
 		fi;
-		if ! ex_rtl_fileop mkdir "${PKG_BUILD_DIR}" "${PKG_DESTDIR}"\
+		if ! rtl_fileop mkdir "${PKG_BUILD_DIR}" "${PKG_DESTDIR}"\
 		|| ! ex_pkg_state_set "${_pkg_name}" "start"; then
 			return "${?}";
 		fi;
 	fi;
-	ex_rtl_fileop cd "${PKG_BUILD_DIR}";
+	rtl_fileop cd "${PKG_BUILD_DIR}";
 };
 
 #
@@ -44,7 +44,7 @@ exp_pkg_exec_pre() {
 exp_pkg_exec_step() {
 	local	_group_name="${1}" _pkg_name="${2}" _restart_at="${3}" _step="${4}"	\
 		_fn_name="" _pkg_step_fn="" _rc=0;
-	if ex_rtl_test_cmd "pkg_${_pkg_name}_${_step}"; then
+	if rtl_test_cmd "pkg_${_pkg_name}_${_step}"; then
 		_pkg_step_fn="pkg_${_pkg_name}_${_step}";
 	else
 		_pkg_step_fn="pkg_${_step}";
@@ -53,7 +53,7 @@ exp_pkg_exec_step() {
 			"pkg_${_pkg_name}_${_step}_pre"	\
 			"${_pkg_step_fn}"		\
 			"pkg_${_pkg_name}_${_step}_post"; do
-		if ex_rtl_test_cmd "${_fn_name}"\
+		if rtl_test_cmd "${_fn_name}"\
 		&& ! "${_fn_name}" "${_group_name}" "${_pkg_name}" "${_restart_at}"; then
 			_rc=1; break;
 		fi;
@@ -80,24 +80,23 @@ ex_pkg_exec() {
 		pkill -U "${$}";								\
 	      fi;" EXIT HUP INT TERM USR1 USR2;
 	if exp_pkg_exec_pre "${_group_name}" "${_pkg_name}" "${_restart_at}"\
-	&& "${_dispatch_fn}" exec_start "${_group_name}" "${_pkg_name}"; then
-		if ex_rtl_test_cmd "pkg_${_pkg_name}_all"; then
+	&& "${_dispatch_fn}" start_pkg_child "${_group_name}" "${_pkg_name}"; then
+		if rtl_test_cmd "pkg_${_pkg_name}_all"; then
 			"pkg_${_pkg_name}_all" "${_restart_at}";
 		else	set -- ${PKG_BUILD_STEPS};
 			while [ ${#} -gt 0 ]; do
 				_step="${1}"; _step_next="${2}"; shift;
-				if ex_pkg_state_test "${_pkg_name}" "${_step}" "${_restart_at}"; then
+				if [ "${PKG_FORCE:-0}" -eq 0 ]\
+				&& ex_pkg_state_test "${_pkg_name}" "${_step}" "${_restart_at}"	; then
 					continue;
 				elif ! exp_pkg_exec_step "${_group_name}" "${_pkg_name}" "${_restart_at}" "${_step}"; then
 					_rc=1; break;
 				else
 					echo "step ${_group_name} ${_pkg_name} ${_step}" >&3;
-					"${_dispatch_fn}" exec_step "${_group_name}" "${_pkg_name}" "${_step}";
 					ex_pkg_state_set "${_pkg_name}" "${_step}" "${_step_next:+-${_step_next}}";
 				fi;
 			done;
 		fi;
-		"${_dispatch_fn}" exec_finish "${_group_name}" "${_pkg_name}";
 		ex_pkg_state_set "${_pkg_name}" finish;
 	fi;
 	return "${_rc}";
diff --git a/subr/ex_rtl.subr b/subr/ex_rtl.subr
deleted file mode 100644
index 1c48bb00..00000000
--- a/subr/ex_rtl.subr
+++ /dev/null
@@ -1,17 +0,0 @@
-#
-# set +o errexit -o noglob is assumed.
-#
-
-EXP_RTL_IFS="${IFS}";
-
-ex_rtl_basename() { echo "${1##*/}"; };
-ex_rtl_date() { command date "+${1:-${DEFAULT_TIMESTAMP_FMT}}"; };
-ex_rtl_dirname() { echo "${1%/*}"; };
-ex_rtl_pop_IFS() { IFS="${EXP_RTL_IFS}"; };
-ex_rtl_push_IFS() { EXP_RTL_IFS="${IFS}"; IFS="${1}"; };
-ex_rtl_set_var_unsafe() { [ -n "${2}" ] && eval ${1}=\"${2}\" || return 0; };
-ex_rtl_test_cmd() { command -v "${1}" >/dev/null; };
-ex_rtl_uniq() { echo "${@}" | sed 's/ /\n/g' | awk '!x[$0]++' | paste -s -d" "; };
-ex_rtl_unset_vars() { while [ ${#} -gt 0 ]; do unset "${1}"; shift; done; };
-
-# vim:filetype=sh
diff --git a/subr/pkg_build.subr b/subr/pkg_build.subr
index e7ea6beb..2433ea81 100644
--- a/subr/pkg_build.subr
+++ b/subr/pkg_build.subr
@@ -10,7 +10,7 @@ pkg_build() {
 	# N.B.	We only specify CC= here if the current package does not use GNU
 	#	autoconf as it often abuses it by appending -std={gnu99,...} to it
 	#	instead of amending CFLAGS.
-	ex_rtl_run_cmd_unsplit make						\
+	rtl_run_cmd_unsplit make						\
 		${PKG_MAKEFLAGS_BUILD}						\
 		${PKG_MAKEFLAGS_BUILD_EXTRA}					\
 		"AR=${PKG_AR}" "${_no_autoconf:+CC=${PKG_CC}}"			\
diff --git a/subr/pkg_clean.subr b/subr/pkg_clean.subr
index 40d56540..b122823e 100644
--- a/subr/pkg_clean.subr
+++ b/subr/pkg_clean.subr
@@ -4,14 +4,14 @@
 
 pkg_clean() {
 	if [ "${PKG_NO_CLEAN:-0}" -eq 0 ]; then
-		if ex_rtl_lmatch "${ARG_CLEAN_BUILDS}" "build" ","; then
-			ex_rtl_fileop rm "${PKG_BUILD_DIR}" || return "${?}";
+		if rtl_lmatch "${ARG_CLEAN_BUILDS}" "build" ","; then
+			rtl_fileop rm "${PKG_BUILD_DIR}" || return "${?}";
 		fi;
-		if ex_rtl_lmatch "${ARG_CLEAN_BUILDS}" "dest" ","; then
-			ex_rtl_fileop rm "${PKG_DESTDIR}" || return "${?}";
+		if rtl_lmatch "${ARG_CLEAN_BUILDS}" "dest" ","; then
+			rtl_fileop rm "${PKG_DESTDIR}" || return "${?}";
 		fi;
-		if ex_rtl_lmatch "${ARG_CLEAN_BUILDS}" "src" ","; then
-			ex_rtl_fileop rm "${PKG_BASE_DIR}/${PKG_SUBDIR}" || return "${?}";
+		if rtl_lmatch "${ARG_CLEAN_BUILDS}" "src" ","; then
+			rtl_fileop rm "${PKG_BASE_DIR}/${PKG_SUBDIR}" || return "${?}";
 		fi;
 	fi;
 };
diff --git a/subr/pkg_configure.subr b/subr/pkg_configure.subr
index 0adc7acf..c6819886 100644
--- a/subr/pkg_configure.subr
+++ b/subr/pkg_configure.subr
@@ -5,7 +5,7 @@
 pkg_configure() {
 	local _rc=0;
 	if [ -x "${PKG_CONFIGURE}" ]; then
-		ex_rtl_export_vars PKG_CONFIG "${PKG_PKG_CONFIG}" PKG_CONFIG_PATH "${PKG_PKG_CONFIG_PATH}" PYTHON "${PKG_PYTHON}";
+		rtl_export_vars PKG_CONFIG "${PKG_PKG_CONFIG}" PKG_CONFIG_PATH "${PKG_PKG_CONFIG_PATH}" PYTHON "${PKG_PYTHON}";
 		AR="${PKG_AR}"												\
 		CC="${PKG_CC}"												\
 		RANLIB="${PKG_RANLIB}"											\
@@ -14,7 +14,7 @@ pkg_configure() {
 		CXXFLAGS="${PKG_CXXFLAGS_CONFIGURE}${PKG_CXXFLAGS_CONFIGURE_EXTRA:+ ${PKG_CXXFLAGS_CONFIGURE_EXTRA}}"	\
 		LDFLAGS="${PKG_LDFLAGS_CONFIGURE}${PKG_LDFLAGS_CONFIGURE_EXTRA:+ ${PKG_LDFLAGS_CONFIGURE_EXTRA}}"	\
 		"${PKG_CONFIGURE}" ${PKG_CONFIGURE_ARGS} ${PKG_CONFIGURE_ARGS_EXTRA} ${PKG_CONFIGURE_ARGS_EXTRA_DEBUG}; _rc="${?}"
-		ex_rtl_export_vars -u PKG_CONFIG "${PKG_PKG_CONFIG}" PKG_CONFIG_PATH "${PKG_PKG_CONFIG_PATH}" PYTHON "${PKG_PYTHON}";
+		rtl_export_vars -u PKG_CONFIG "${PKG_PKG_CONFIG}" PKG_CONFIG_PATH "${PKG_PKG_CONFIG_PATH}" PYTHON "${PKG_PYTHON}";
 	fi;
 	return "${?}";
 };
diff --git a/subr/pkg_configure_autotools.subr b/subr/pkg_configure_autotools.subr
index 7c1ee329..bc3b6c23 100644
--- a/subr/pkg_configure_autotools.subr
+++ b/subr/pkg_configure_autotools.subr
@@ -4,9 +4,9 @@
 
 pkg_configure_autotools() {
 	local _config_cache="" _fname="" _subdir_tgt="";
-	if ex_rtl_exists_any "${PKG_BASE_DIR}/${PKG_SUBDIR}"							\
+	if rtl_exists_any "${PKG_BASE_DIR}/${PKG_SUBDIR}"							\
 			"config.guess" "configure.ac" "configure.in" "configure";
-	then	ex_rtl_export_vars PKG_CONFIG "${PKG_PKG_CONFIG}" PKG_CONFIG_PATH "${PKG_PKG_CONFIG_PATH}";
+	then	rtl_export_vars PKG_CONFIG "${PKG_PKG_CONFIG}" PKG_CONFIG_PATH "${PKG_PKG_CONFIG_PATH}";
 		if [ -e "${PKG_BASE_DIR}/${PKG_SUBDIR}/configure.ac" ]\
 		&& [ ! -e "${PKG_BASE_DIR}/${PKG_SUBDIR}/configure" ]; then
 			for _fname in bootstrap bootstrap.sh autogen.sh; do
@@ -15,25 +15,25 @@ pkg_configure_autotools() {
 							"${PKG_BASE_DIR}/${PKG_SUBDIR}/build-aux"		\
 							"${PKG_BASE_DIR}/${PKG_SUBDIR}";
 					do	if [ -e "${_subdir_tgt}" ]; then
-							ex_rtl_fileop install -m 0700				\
+							rtl_fileop install -m 0700				\
 								"${MIDIPIX_BUILD_PWD}/etc/config.sub"		\
 								"${_subdir_tgt}/config.sub" || return "${?}" && break;
 						fi;
 					done;
-					(ex_rtl_fileop cd "${PKG_BASE_DIR}/${PKG_SUBDIR}" &&			\
+					(rtl_fileop cd "${PKG_BASE_DIR}/${PKG_SUBDIR}" &&			\
 						/bin/sh "${_fname}") || return "${?}" && break;
 				fi;
 			done;
-			(ex_rtl_fileop cd "${PKG_BASE_DIR}/${PKG_SUBDIR}" && autoconf) || return "${?}";
+			(rtl_fileop cd "${PKG_BASE_DIR}/${PKG_SUBDIR}" && autoconf) || return "${?}";
 		fi;
 		for _fname in $(find "${PKG_BASE_DIR}/${PKG_SUBDIR}" -name config.sub); do
-			if ! ex_rtl_fileop mv "${_fname}" "${_fname}.orig"\
-			|| ! ex_rtl_fileop install -m 0700 "${MIDIPIX_BUILD_PWD}/etc/config.sub" "${_fname}"; then
+			if ! rtl_fileop mv "${_fname}" "${_fname}.orig"\
+			|| ! rtl_fileop install -m 0700 "${MIDIPIX_BUILD_PWD}/etc/config.sub" "${_fname}"; then
 				return 1;
 			fi;
 		done
 		if [ "${PKG_BUILD_TYPE}" != host ]; then
-			if ! ex_rtl_fileop touch "${PKG_BUILD_DIR}/config.cache"; then
+			if ! rtl_fileop touch "${PKG_BUILD_DIR}/config.cache"; then
 				return 1;
 			else	for _config_cache in \
 						"${PKG_CONFIG_CACHE}"						\
@@ -45,7 +45,7 @@ pkg_configure_autotools() {
 				sed -i"" "s,%PREFIX%,${PKG_PREFIX},g" "${PKG_BUILD_DIR}/config.cache" || return "${?}";
 			fi;
 		fi;
-		ex_rtl_export_vars -u PKG_CONFIG "${PKG_PKG_CONFIG}" PKG_CONFIG_PATH "${PKG_PKG_CONFIG_PATH}";
+		rtl_export_vars -u PKG_CONFIG "${PKG_PKG_CONFIG}" PKG_CONFIG_PATH "${PKG_PKG_CONFIG_PATH}";
 	fi;
 };
 
diff --git a/subr/pkg_configure_patch.subr b/subr/pkg_configure_patch.subr
index 366a9e52..80690b67 100644
--- a/subr/pkg_configure_patch.subr
+++ b/subr/pkg_configure_patch.subr
@@ -12,9 +12,9 @@ pkg_configure_patch() {
 			"${_patch_dir}/${_pkg_name_full}.local@${BUILD_HNAME}.patch"	\
 			${PKG_PATCHES_EXTRA}; do
 		if [ -r "${_patch_fname}" ]\
-		&& ! ex_rtl_lmatch "${_patches_done}" "${_patch_fname}"; then
+		&& ! rtl_lmatch "${_patches_done}" "${_patch_fname}"; then
 			patch -b -d "${PKG_BASE_DIR}/${PKG_SUBDIR}" -p1 < "${_patch_fname}" || return "${?}";
-			_patches_done="$(ex_rtl_lconcat "${_patches_done}" "${_patch_fname}")";
+			_patches_done="$(rtl_lconcat "${_patches_done}" "${_patch_fname}")";
 		fi;
 	done; set -o noglob;
 };
diff --git a/subr/pkg_configure_patch_pre.subr b/subr/pkg_configure_patch_pre.subr
index f38b5188..1c572efd 100644
--- a/subr/pkg_configure_patch_pre.subr
+++ b/subr/pkg_configure_patch_pre.subr
@@ -17,8 +17,8 @@ pkgp_configure_patch_pre_chainport() {
 	local	_chainport_patch_fname="${BUILD_WORKDIR}/chainport/patches/${PKG_NAME%%_*}/${PKG_NAME%%_*}-${PKG_VERSION}.midipix.patch"\
 		_chainport_patch_dname="${PKG_BASE_DIR}/${PKG_SUBDIR}/patches/${PKG_NAME%%_*}" _oldpwd="";
 	if [ -e "${_chainport_patch_fname}" ]; then
-		ex_rtl_fileop mkdir "${_chainport_patch_dname}" || return "${?}";
-		ex_rtl_fileop cp "${_chainport_patch_fname}" "${_chainport_patch_dname}" || return "${?}";
+		rtl_fileop mkdir "${_chainport_patch_dname}" || return "${?}";
+		rtl_fileop cp "${_chainport_patch_fname}" "${_chainport_patch_dname}" || return "${?}";
 	fi;
 };
 
diff --git a/subr/pkg_fetch_download.subr b/subr/pkg_fetch_download.subr
index 8e1d193b..a23b8b9d 100644
--- a/subr/pkg_fetch_download.subr
+++ b/subr/pkg_fetch_download.subr
@@ -4,10 +4,10 @@
 
 pkg_fetch_download() {
 	if [ -n "${PKG_URL}" ]; then
-		ex_rtl_fetch_url_wget "${PKG_URL}" "${PKG_SHA256SUM}" "${PKG_FNAME}" || return "${?}";
+		rtl_fetch_url_wget "${PKG_URL}" "${PKG_SHA256SUM}" "${PKG_FNAME}" || return "${?}";
 	fi;
 	if [ -n "${PKG_URLS_GIT}" ]; then
-		ex_rtl_fetch_urls_git "${PKG_BASE_DIR}" ${PKG_URLS_GIT} || return "${?}";
+		rtl_fetch_urls_git "${PKG_BASE_DIR}" ${PKG_URLS_GIT} || return "${?}";
 	fi;
 };
 
diff --git a/subr/pkg_fetch_extract.subr b/subr/pkg_fetch_extract.subr
index 66e51669..9df9f93e 100644
--- a/subr/pkg_fetch_extract.subr
+++ b/subr/pkg_fetch_extract.subr
@@ -14,8 +14,8 @@ pkgp_fetch_extract_type() {
 pkg_fetch_extract() {
 	if [ -n "${PKG_URL}" ]\
 	&& [ "${PKG_URL_TYPE:-wget}" = wget ]; then
-		_oldpwd="${PWD}"; ex_rtl_fileop cd "${PKG_BASE_DIR}" || return "${?}";
-		ex_rtl_fileop rm "${PKG_BASE_DIR}/${PKG_SUBDIR}" || return "${?}";
+		_oldpwd="${PWD}"; rtl_fileop cd "${PKG_BASE_DIR}" || return "${?}";
+		rtl_fileop rm "${PKG_BASE_DIR}/${PKG_SUBDIR}" || return "${?}";
 		case "$(pkgp_fetch_extract_type "${PKG_NAME}")" in
 		bz2)	bunzip2 -d < "${BUILD_DLCACHEDIR}/${PKG_FNAME}" | tar -C "${PKG_BASE_DIR}" -xf - || return "${?}"; ;;
 		gz)	gunzip -d < "${BUILD_DLCACHEDIR}/${PKG_FNAME}" | tar -C "${PKG_BASE_DIR}" -xf - || return "${?}"; ;;
@@ -23,7 +23,7 @@ pkg_fetch_extract() {
 		xz)	xz -d < "${BUILD_DLCACHEDIR}/${PKG_FNAME}" | tar -C "${PKG_BASE_DIR}" -xf - || return "${?}"; ;;
 		*)	tar -C "${PKG_BASE_DIR}" -xf "${BUILD_DLCACHEDIR}/${PKG_FNAME}" || return "${?}"; ;;
 		esac;
-		ex_rtl_fileop cd "${_oldpwd}" || return "${?}";
+		rtl_fileop cd "${_oldpwd}" || return "${?}";
 	fi;
 };
 
diff --git a/subr/pkg_install.subr b/subr/pkg_install.subr
index 46024e8e..87182d9c 100644
--- a/subr/pkg_install.subr
+++ b/subr/pkg_install.subr
@@ -4,14 +4,14 @@
 
 pkg_install() {
 	local _pkglist_name="";
-	if ! ex_rtl_fileop mkdir "${PKG_PREFIX}"\
+	if ! rtl_fileop mkdir "${PKG_PREFIX}"\
 	|| ! find "${PKG_DESTDIR}" -type d -exec chmod 0755 {} \;\
 	|| ! find "${PKG_DESTDIR}" \( -not -perm /0111 \) -type f -exec chmod 0644 {} \;\
 	|| ! find "${PKG_DESTDIR}" -perm /0111 -type f -exec chmod 0755 {} \;\
 	|| ! tar -C "${PKG_DESTDIR}" -cpf - . | tar -C "${PKG_PREFIX}" --overwrite -xpf -; then
 		return "${?}";
 	else
-		if ex_rtl_lmatch "${ARG_DIST}" "pkg" ","; then
+		if rtl_lmatch "${ARG_DIST}" "pkg" ","; then
 			tar -C "${PKG_DESTDIR}" -cpf - . |\
 				gzip -c -9 - > "${PKG_BASE_DIR}/${PKG_NAME}.tgz" || return "${?}";
 		fi;
diff --git a/subr/pkg_install_files.subr b/subr/pkg_install_files.subr
index 92c7ed7e..5a4d9708 100644
--- a/subr/pkg_install_files.subr
+++ b/subr/pkg_install_files.subr
@@ -4,7 +4,7 @@
 
 pkgp_install_files() {
 	if [ -n "${PKG_INSTALL_FILES}" ]; then
-		ex_rtl_install -v "${PKG_DESTDIR}" ${PKG_INSTALL_FILES} || return "${?}";
+		rtl_install -v "${PKG_DESTDIR}" ${PKG_INSTALL_FILES} || return "${?}";
 	fi;
 };
 
@@ -30,7 +30,7 @@ pkgp_install_files_strip() {
 		fi;
 		for _bin_path in $(find "${_tree_root}" -perm /a=x -type f); do
 			if objdump -sj .debug_info "${_bin_path}" >/dev/null 2>&1; then
-				ex_rtl_log_msg info "Stripping ${_bin_path}...";
+				rtl_log_msg info "Stripping ${_bin_path}...";
 				"${PKG_TARGET}-strip" "${_bin_path}" || return "${?}";
 			fi;
 		done;
diff --git a/subr/pkg_install_libs.subr b/subr/pkg_install_libs.subr
index 379a0374..a00f15bb 100644
--- a/subr/pkg_install_libs.subr
+++ b/subr/pkg_install_libs.subr
@@ -5,7 +5,7 @@
 pkgp_install_libs_purge_la() {
 	local _la_path="";
 	for _la_path in $(find "${PKG_DESTDIR}" -type f -name \*.la); do
-		ex_rtl_fileop rm "${_la_path}" || return "${?}";
+		rtl_fileop rm "${_la_path}" || return "${?}";
 	done;
 };
 
@@ -14,8 +14,8 @@ pkgp_install_libs_shared_link() {
 	if _lib_link_tgt="$(find "${_so_dir}" -name "${_lib_name%%.*}.*.lib.a" | sort | tail -1)"\
 	&& [ -n "${_lib_link_tgt}" ]\
 	&& [ "${_lib_link_tgt}" != "${_lib_link_path}" ]; then
-		if ! ex_rtl_fileop rm "${_lib_link_path}"\
-		|| ! ex_rtl_fileop ln_symbolic "$(ex_rtl_basename "${_lib_link_tgt}")" "${_lib_link_path}"; then
+		if ! rtl_fileop rm "${_lib_link_path}"\
+		|| ! rtl_fileop ln_symbolic "$(rtl_basename "${_lib_link_tgt}")" "${_lib_link_path}"; then
 			return 1;
 		fi;
 	fi;
@@ -28,21 +28,21 @@ pkgp_install_libs_shared() {
 			$(find	"${PKG_DESTDIR}"							  \
 				\(  -name "*.so" -or -name "*.so.*" \) -print);
 		do	if [ "$(readlink -f "${_so_path}")" != "/dev/null" ]\
-			&& [ -z "$(ex_rtl_head "[0-9.]" "${_so_src_path##*.so}")" ]; then
+			&& [ -z "$(rtl_head "[0-9.]" "${_so_src_path##*.so}")" ]; then
 				case "${_so_src_path}" in
 				*.so)	_lib_src_path="${_so_src_path%%.so}.lib.a"; ;;
 				*.so.*)	_lib_src_path="${_so_src_path%%.so.*}.${_so_src_path##*.so.}.lib.a"; ;;
 				esac;
 				_so_dst_dir="${_so_src_path%/*}";
-				_lib_name="$(ex_rtl_basename "${_lib_src_path}")";
+				_lib_name="$(rtl_basename "${_lib_src_path}")";
 				_lib_dst_path="${_so_dst_dir}/${_lib_name}";
 				if [ ! -L "${_lib_src_path}" ]\
 				&& [ ! -e "${_lib_dst_path}" ]; then
-					(ex_rtl_fileop cd "$(ex_rtl_dirname "${_so_src_path}")" 	&&\
-					perk -e "$(ex_rtl_basename "${_so_src_path}")"			 |\
+					(rtl_fileop cd "$(rtl_dirname "${_so_src_path}")" 	&&\
+					perk -e "$(rtl_basename "${_so_src_path}")"			 |\
 						"${PKG_TARGET}-mdso"					  \
-							-i "$(ex_rtl_basename "${_lib_dst_path}")"	  \
-							-n "$(ex_rtl_basename "${_so_src_path}")" -) || return "${?}";
+							-i "$(rtl_basename "${_lib_dst_path}")"	  \
+							-n "$(rtl_basename "${_so_src_path}")" -) || return "${?}";
 				fi;
 				pkgp_install_libs_shared_link "${_lib_name}" "${_so_dst_dir}" "${_so_src_path}" || return "${?}";
 			fi;
diff --git a/subr/pkg_install_make.subr b/subr/pkg_install_make.subr
index 5cf16fe9..45f5d58f 100644
--- a/subr/pkg_install_make.subr
+++ b/subr/pkg_install_make.subr
@@ -3,7 +3,7 @@
 #
 
 pkg_install_make() {
-	ex_rtl_run_cmd_unsplit make							\
+	rtl_run_cmd_unsplit make							\
 		${PKG_MAKEFLAGS_INSTALL}						\
 		${PKG_MAKEFLAGS_INSTALL_EXTRA}						\
 		AR=${PKG_AR} CC=${PKG_CC} RANLIB=${PKG_RANLIB}				\
diff --git a/subr/pkg_install_rpm.subr b/subr/pkg_install_rpm.subr
index b3c939ab..ae76ac70 100644
--- a/subr/pkg_install_rpm.subr
+++ b/subr/pkg_install_rpm.subr
@@ -4,7 +4,7 @@
 
 pkg_install_rpm() {
 	local _pkg_url="" _pkg_version_full="" _pkg_version_rpm="" _rc=0;
-	if ex_rtl_lmatch "${ARG_DIST}" "rpm" ","\
+	if rtl_lmatch "${ARG_DIST}" "rpm" ","\
 	&& [ "${PKG_RPM_DISABLE:-0}" -eq 0 ]\
 	&& [ -x "$(which rpmbuild 2>/dev/null)" ]; then
 		if [ -n "${PKG_URL}" ]; then
@@ -17,7 +17,7 @@ pkg_install_rpm() {
 				_pkg_url="Unknown";
 			fi;
 		fi;
-		if ! ex_rtl_fileop cp "${MIDIPIX_BUILD_PWD}/etc/package.spec"					\
+		if ! rtl_fileop cp "${MIDIPIX_BUILD_PWD}/etc/package.spec"					\
 				"${PKG_BASE_DIR}/${PKG_NAME}-${_pkg_version_rpm}.spec"; then
 			return 1;
 		else	while true; do
@@ -41,8 +41,8 @@ pkg_install_rpm() {
 			done;
 			if ! find "${PREFIX_RPM}/${PKG_NAME}-${_pkg_version_rpm}/RPMS"				\
 				-iname \*.rpm -exec cp -pP {} "${PREFIX_RPM}/" \;				\
-			|| ! ex_rtl_fileop rm "${PREFIX_RPM}/${PKG_NAME}-${_pkg_version_rpm}"			\
-			|| ! ex_rtl_fileop cp "${PKG_BASE_DIR}/${PKG_NAME}-${_pkg_version_rpm}.spec" "${PREFIX_RPM}/"; then
+			|| ! rtl_fileop rm "${PREFIX_RPM}/${PKG_NAME}-${_pkg_version_rpm}"			\
+			|| ! rtl_fileop cp "${PKG_BASE_DIR}/${PKG_NAME}-${_pkg_version_rpm}.spec" "${PREFIX_RPM}/"; then
 				return "${?}";
 			fi;
 		fi;
diff --git a/subr/pkg_install_subdirs.subr b/subr/pkg_install_subdirs.subr
index 379592f5..94557586 100644
--- a/subr/pkg_install_subdirs.subr
+++ b/subr/pkg_install_subdirs.subr
@@ -7,10 +7,10 @@ pkg_install_subdirs() {
 	for _spec in \
 			"${PKG_INSTALL_FILES_DESTDIR}"		\
 			"${PKG_INSTALL_FILES_DESTDIR_EXTRA}"; do
-		ex_rtl_install "${PKG_DESTDIR}" ${_spec} || return "${?}";
+		rtl_install "${PKG_DESTDIR}" ${_spec} || return "${?}";
 	done;
 	if [ "${PKG_PREFIX%/}" = "${PREFIX_NATIVE%/}" ]; then
-		ex_rtl_install					\
+		rtl_install					\
 			"${PKG_DESTDIR}/${DEFAULT_TARGET}" ${PKG_INSTALL_FILES_DESTDIR} || return "${?}";
 	fi;
 };
diff --git a/subr/rtl.subr b/subr/rtl.subr
new file mode 100644
index 00000000..18ddb8d6
--- /dev/null
+++ b/subr/rtl.subr
@@ -0,0 +1,17 @@
+#
+# set +o errexit -o noglob is assumed.
+#
+
+EXP_RTL_IFS="${IFS}";
+
+rtl_basename() { echo "${1##*/}"; };
+rtl_date() { command date "+${1:-${DEFAULT_TIMESTAMP_FMT}}"; };
+rtl_dirname() { echo "${1%/*}"; };
+rtl_pop_IFS() { IFS="${EXP_RTL_IFS}"; };
+rtl_push_IFS() { EXP_RTL_IFS="${IFS}"; IFS="${1}"; };
+rtl_set_var_unsafe() { [ -n "${2}" ] && eval ${1}=\"${2}\" || return 0; };
+rtl_test_cmd() { command -v "${1}" >/dev/null; };
+rtl_uniq() { echo "${@}" | sed 's/ /\n/g' | awk '!x[$0]++' | paste -s -d" "; };
+rtl_unset_vars() { while [ ${#} -gt 0 ]; do unset "${1}"; shift; done; };
+
+# vim:filetype=sh
diff --git a/subr/ex_rtl_complex.subr b/subr/rtl_complex.subr
index 682a950e..6d9750dc 100644
--- a/subr/ex_rtl_complex.subr
+++ b/subr/rtl_complex.subr
@@ -2,10 +2,10 @@
 # set +o errexit -o noglob is assumed.
 #
 
-ex_rtl_check_path_vars() {
+rtl_check_path_vars() {
 	local _vnames="${1}" _rc=0 _vname="" _vname_val=""; _status="";
 	for _vname in ${_vnames}; do
-		_vname_val="$(ex_rtl_get_var_unsafe "${_vname}")";
+		_vname_val="$(rtl_get_var_unsafe "${_vname}")";
 		if [ -z "${_vname_val}" ]; then
 			_rc=1; _status="Error: variable \`${_vname}' is empty or unset."; break;
 		elif [ "${_vname_val#* *}" != "${_vname_val}" ]; then
@@ -15,7 +15,7 @@ ex_rtl_check_path_vars() {
 	return "${_rc}";
 };
 
-ex_rtl_clean_env() {
+rtl_clean_env() {
 	local _env_vars_except="${1}" _env_var="" _env_vars="";
 	_env_vars="$(export | sed -ne '/^export/{s/^export //;s/=.*$//p}')";
 	for _env_var in ${_env_vars}; do
@@ -24,10 +24,10 @@ ex_rtl_clean_env() {
 			_env_vars_except="${_env_vars_except:+${_env_vars_except} }${_env_var}";
 		fi;
 	done;
-	ex_rtl_unset_vars $(ex_rtl_lfilter "${_env_vars}" "${_env_vars_except}");
+	rtl_unset_vars $(rtl_lfilter "${_env_vars}" "${_env_vars_except}");
 };
 
-ex_rtl_exists_any() {
+rtl_exists_any() {
 	local _subdir="${1}"; shift;
 	while [ "${#}" -gt 0 ]; do
 		if [ -e "${_subdir}/${1}" ]; then
@@ -38,12 +38,12 @@ ex_rtl_exists_any() {
 	done; return 1;
 };
 
-ex_rtl_export_vars() {
+rtl_export_vars() {
 	local _unsetfl=0; [ "x${1}" = "x-u" ] && { _unsetfl=1; shift; };
 	while [ "${#}" -ge 2 ]; do
 		if [ -n "${2}" ]; then
 			if [ "${_unsetfl:-0}" -eq 0 ]; then
-				ex_rtl_set_var_unsafe "${1}" "${2}"; export "${1}";
+				rtl_set_var_unsafe "${1}" "${2}"; export "${1}";
 			else
 				unset "${1}";
 			fi;
@@ -52,17 +52,17 @@ ex_rtl_export_vars() {
 	done;
 };
 
-ex_rtl_get_var_unsafe() {
+rtl_get_var_unsafe() {
 	local _vname="";
 	if [ "x${1}" = "x-u" ]; then
-		shift; _vname="$(ex_rtl_toupper "${1}")";
+		shift; _vname="$(rtl_toupper "${1}")";
 	else
 		_vname="${1}";
 	fi;
 	eval echo \${${_vname}};
 };
 
-ex_rtl_head() {
+rtl_head() {
 	local _pattern="${1}" _s="${2}";
 	while true; do
 		if [ "${_s%%${_pattern}}" = "${_s}" ]; then
@@ -74,7 +74,7 @@ ex_rtl_head() {
 	echo "${_s}";
 };
 
-ex_rtl_kill_tree() {
+rtl_kill_tree() {
 	local _pid="${1}" _signal="TERM" _pid_child="" _pid_top="";
 	for _pid_top in $(pgrep -P "${_pid}"); do
 		for _pid_child in $(pgrep -P "${_pid_top}" 2>/dev/null); do
@@ -84,7 +84,7 @@ ex_rtl_kill_tree() {
 	done;
 };
 
-ex_rtl_run_cmd_unsplit() {
+rtl_run_cmd_unsplit() {
 	local _cmd="${1}" _cmdline="" _rc="" IFS; shift;
 	while [ ${#} -gt 0 ]; do
 		[ -n "${1}" ] &&\
@@ -95,19 +95,19 @@ ex_rtl_run_cmd_unsplit() {
 	return ${_rc};
 };
 
-ex_rtl_set_vars() {
+rtl_set_vars() {
 	local	_vars_set_vname="${1}" _vname_dst="${2}" _vname_src_tmpls="${3}"	\
 		_vars_set_old="" _vars_set_tmp="" _vname_src="";
-	for _vname_src in $(ex_rtl_toupper "${_vname_src_tmpls}"); do
+	for _vname_src in $(rtl_toupper "${_vname_src_tmpls}"); do
 		_vname_src="${_vname_src}_${_vname_dst}";
-		_vval_src="$(ex_rtl_get_var_unsafe "${_vname_src}")";
+		_vval_src="$(rtl_get_var_unsafe "${_vname_src}")";
 		if [ -n "${_vval_src}" ]; then
-			ex_rtl_set_var_unsafe "PKG_${_vname_dst}" "${_vval_src}";
+			rtl_set_var_unsafe "PKG_${_vname_dst}" "${_vval_src}";
 			_vars_set_tmp="${_vars_set_tmp:+${_vars_set_tmp} }PKG_${_vname_dst}";
 		fi;
 	done;
-	_vars_set_old="$(ex_rtl_get_var_unsafe "${_vars_set_vname}")";
-	ex_rtl_set_var_unsafe "${_vars_set_vname}"					\
+	_vars_set_old="$(rtl_get_var_unsafe "${_vars_set_vname}")";
+	rtl_set_var_unsafe "${_vars_set_vname}"					\
 		"${_vars_set_old:+${_vars_set_old} }${_vars_set_tmp}";
 };
 
diff --git a/subr/ex_rtl_fetch.subr b/subr/rtl_fetch.subr
index c4ba862d..d61d7858 100644
--- a/subr/ex_rtl_fetch.subr
+++ b/subr/rtl_fetch.subr
@@ -16,23 +16,23 @@ exp_rtl_fetch_url_git() {
 		fi;
 	done;
 	if [ -e "${BUILD_DLCACHEDIR}/${_subdir}" ]; then
-		(ex_rtl_fileop cd "${BUILD_DLCACHEDIR}/${_subdir}" &&\
+		(rtl_fileop cd "${BUILD_DLCACHEDIR}/${_subdir}" &&\
 			git pull ${DEFAULT_GIT_ARGS} origin "${_branch:-main}");
-		(ex_rtl_fileop cd "${BUILD_DLCACHEDIR}/${_subdir}" &&\
+		(rtl_fileop cd "${BUILD_DLCACHEDIR}/${_subdir}" &&\
 			git submodule update);
 	else
 		git clone ${DEFAULT_GIT_ARGS} "${_url}" "${BUILD_DLCACHEDIR}/${_subdir}";
 		if [ -n "${_branch}" ]; then
-			(ex_rtl_fileop cd "${BUILD_DLCACHEDIR}/${_subdir}" &&\
+			(rtl_fileop cd "${BUILD_DLCACHEDIR}/${_subdir}" &&\
 				git checkout "${_branch}");
 		fi;
-		(ex_rtl_fileop cd "${BUILD_DLCACHEDIR}/${_subdir}" &&\
+		(rtl_fileop cd "${BUILD_DLCACHEDIR}/${_subdir}" &&\
 			git submodule update --init);
 	fi;
-	_oldpwd="${PWD}"; ex_rtl_fileop cd "${PKG_BASE_DIR}";
-	ex_rtl_fileop rm "${_tgtdir}/${_subdir}";
-	ex_rtl_fileop cp "${BUILD_DLCACHEDIR}/${_subdir}" "${_tgtdir}";
-	ex_rtl_fileop cd "${_oldpwd}";) 4<>"${BUILD_DLCACHEDIR}/${_subdir%%[/]}.fetching";
+	_oldpwd="${PWD}"; rtl_fileop cd "${PKG_BASE_DIR}";
+	rtl_fileop rm "${_tgtdir}/${_subdir}";
+	rtl_fileop cp "${BUILD_DLCACHEDIR}/${_subdir}" "${_tgtdir}";
+	rtl_fileop cd "${_oldpwd}";) 4<>"${BUILD_DLCACHEDIR}/${_subdir%%[/]}.fetching";
 	if [ "${?}" -eq 0 ]; then
 		cd "$(pwd)";
 	else
@@ -40,7 +40,7 @@ exp_rtl_fetch_url_git() {
 	fi;
 };
 
-ex_rtl_fetch_urls_git() {
+rtl_fetch_urls_git() {
 	local _tgtdir="" _url_spec="" _subdir="" _url="" _git_branch="";
 	_tgtdir="${1}"; shift;
 	if [ "${ARG_FETCH_FORCE}" = "offline" ]; then
@@ -59,12 +59,12 @@ ex_rtl_fetch_urls_git() {
 };
 
 # N.B.	URLs ($1) may contain `?' or '&' characters.
-ex_rtl_fetch_url_wget() {
+rtl_fetch_url_wget() {
 	local _url="${1}" _sha256sum_src="${2}" _target_fname="${3}" _sha256sum_dst="";
 	if [ "${ARG_FETCH_FORCE}" = "offline" ]; then
 		return 0;
 	elif [ -z "${_target_fname}" ]; then
-		_target_fname="$(ex_rtl_basename "${_url}")";
+		_target_fname="$(rtl_basename "${_url}")";
 	fi;
 	_url_dst="${BUILD_DLCACHEDIR}/${_target_fname}";
 	(set -o errexit -o noglob; trap "_rc=\"\${?}\" ;rm -f \"${_url_dst}.fetching\"; exit \"\${_rc}\";" EXIT;
@@ -82,10 +82,10 @@ ex_rtl_fetch_url_wget() {
 		if [ -n "${_sha256sum_src}" ]; then
 			set -- $(sha256sum "${_url_dst}");
 			if [ "${_sha256sum_dst:=${1}}" != "${_sha256sum_src}" ]; then
-				ex_rtl_log_msg failexit "Error: hash mismatch for URL \`${_url}' (downloaded file: ${_sha256sum_dst}, from build variables: ${_sha256sum_src}.)";
+				rtl_log_msg failexit "Error: hash mismatch for URL \`${_url}' (downloaded file: ${_sha256sum_dst}, from build variables: ${_sha256sum_src}.)";
 			fi;
 		fi;
-		ex_rtl_fileop touch "${_url_dst}.fetched";
+		rtl_fileop touch "${_url_dst}.fetched";
 	fi;) 4<>"${_url_dst}.fetching";
 };
 
diff --git a/subr/ex_rtl_fileop.subr b/subr/rtl_fileop.subr
index 417ec261..cc861787 100644
--- a/subr/ex_rtl_fileop.subr
+++ b/subr/rtl_fileop.subr
@@ -9,90 +9,90 @@ exp_rtl_fileop_check() {
 	shift; done;
 };
 
-ex_rtl_fileop() {
+rtl_fileop() {
 	local _op="${1}" _dst="" _install_args="" _rc=0 _src=""; shift;
 	case "${_op}" in
 	cd)	if [ \( -z "${1}" \) -o ! \( -L "${1}" -o -e "${1}" \) ]; then
-			ex_rtl_log_msg failexit "Invalid or non-existent directory \`${1}'.";
+			rtl_log_msg failexit "Invalid or non-existent directory \`${1}'.";
 		elif exp_rtl_fileop_check "${PREFIX}" "${1}"; then
-			ex_rtl_log_msg vvvv "Changing working directory to \`${1}'.";
+			rtl_log_msg vvvv "Changing working directory to \`${1}'.";
 			cd -- "${1}"; _rc="${?}";
 		fi; ;;
 	cp_follow)
 		if [ "${#}" -lt 2 ]; then
-			ex_rtl_log_msg failexit "Missing parameters (in: cp_follow ${*}.)";
+			rtl_log_msg failexit "Missing parameters (in: cp_follow ${*}.)";
 		elif exp_rtl_fileop_check "${PREFIX}" "${*}"; then
 			_src="${*}"; _src="${_src% *}";
 			_dst="${*}"; _dst="${_dst##* }";
-			ex_rtl_log_msg vvvv "Copying \`${_src}' into \`${_dst}' w/ -pLR.";
+			rtl_log_msg vvvv "Copying \`${_src}' into \`${_dst}' w/ -pLR.";
 			cp -pLR -- "${@}"; _rc="${?}";
 		fi; ;;
 	cp)	if [ "${#}" -lt 2 ]; then
-			ex_rtl_log_msg failexit "Missing parameters (in: cp ${*}.)";
+			rtl_log_msg failexit "Missing parameters (in: cp ${*}.)";
 		elif exp_rtl_fileop_check "${PREFIX}" "${*}"; then
 			_src="${*}"; _src="${_src% *}";
 			_dst="${*}"; _dst="${_dst##* }";
-			ex_rtl_log_msg vvvv "Copying \`${_src}' into \`${_dst}' w/ -pPR.";
+			rtl_log_msg vvvv "Copying \`${_src}' into \`${_dst}' w/ -pPR.";
 			cp -pPR -- "${@}"; _rc="${?}";
 		fi; ;;
 	install)
 		if [ "${#}" -lt 2 ]; then
-			ex_rtl_log_msg failexit "Missing parameters (in: install ${*}.)";
+			rtl_log_msg failexit "Missing parameters (in: install ${*}.)";
 		else	_dst="$(while [ ""${#}"" -gt 2 ]; do shift; done; echo "${2}")";
 			_install_args="$(while [ ""${#}"" -gt 2 ]; do echo "${1}"; shift; done)";
 			_src="$(while [ ""${#}"" -gt 2 ]; do shift; done; echo "${1}")";
 			if exp_rtl_fileop_check "${PREFIX}" "${_dst}" "${_src}"; then
-				ex_rtl_log_msg vvvv "Installing \`${_src}' into \`${_dst}' w/ ${_install_args}.";
+				rtl_log_msg vvvv "Installing \`${_src}' into \`${_dst}' w/ ${_install_args}.";
 				install "${@}"; _rc="${?}";
 			fi;
 		fi; ;;
 	ln_symbolic)
 		if [ \( -z "${1}" \) -o \( -z "${2}" \) ]; then
-			ex_rtl_log_msg failexit "Missing parameters (in: ln_symbolic ${*}.)";
+			rtl_log_msg failexit "Missing parameters (in: ln_symbolic ${*}.)";
 		elif exp_rtl_fileop_check "${PREFIX}" "${2}"; then
-			if ex_rtl_fileop test "${2}"; then
-				ex_rtl_fileop rm "${2}";
+			if rtl_fileop test "${2}"; then
+				rtl_fileop rm "${2}";
 			fi;
 			if [ "${?}" -eq 0 ]; then
-				ex_rtl_log_msg vvvv "Linking \`${1}' to \`${2}' w/ -fs";
+				rtl_log_msg vvvv "Linking \`${1}' to \`${2}' w/ -fs";
 				ln -fs -- "${1}" "${2}"; _rc="${?}";
 			fi;
 		fi; ;;
 	mv)	if [ \( -z "${1}" \) -o \( -z "${2}" \) ]; then
-			ex_rtl_log_msg failexit "Missing parameters (in: mv ${*}.)";
+			rtl_log_msg failexit "Missing parameters (in: mv ${*}.)";
 		elif exp_rtl_fileop_check "${PREFIX}" "${1}" "${2}"; then
-			ex_rtl_log_msg vvvv "Moving \`${1}' to \`${2}' w/ -fs";
+			rtl_log_msg vvvv "Moving \`${1}' to \`${2}' w/ -fs";
 			mv -f -- "${1}" "${2}"; _rc="${?}";
 		fi; ;;
 	mkdir|mkfifo|rm|source_opt|test|touch)
 		while [ \( "${?}" -eq 0 \) -a \( ""${#}"" -gt 0 \) ]; do
 			if [ -z "${1}" ]; then
-				ex_rtl_log_msg failexit "Missing parameters (in: ${_op} ${*}.)";
+				rtl_log_msg failexit "Missing parameters (in: ${_op} ${*}.)";
 			elif [ "${_op}" = mkdir ]\
 			&& [ ! -d "${1}" ]\
 			&& exp_rtl_fileop_check "${PREFIX}" "${1}"; then
-				if ex_rtl_fileop test "${1}"; then
-					ex_rtl_fileop rm "${1}";
+				if rtl_fileop test "${1}"; then
+					rtl_fileop rm "${1}";
 				fi;
-				ex_rtl_log_msg vvvv "Making directory \`${1}'.";
+				rtl_log_msg vvvv "Making directory \`${1}'.";
 				mkdir -p -- "${1}"; _rc="${?}";
 			elif [ "${_op}" = mkfifo ]\
 			&& exp_rtl_fileop_check "${PREFIX}" "${1}"; then
-				if ex_rtl_fileop test "${1}"; then
-					ex_rtl_fileop rm "${1}";
+				if rtl_fileop test "${1}"; then
+					rtl_fileop rm "${1}";
 				fi;
-				ex_rtl_log_msg vvvv "Creating FIFO \`${1}'.";
+				rtl_log_msg vvvv "Creating FIFO \`${1}'.";
 				exp_rtl_fileop_check "${PREFIX}" "${1}";
 				mkfifo -- "${1}"; _rc="${?}";
 			elif [ "${_op}" = rm ]\
-			&& ex_rtl_fileop test "${1}"\
+			&& rtl_fileop test "${1}"\
 			&& exp_rtl_fileop_check "${PREFIX}" "${1}"; then
-				ex_rtl_log_msg vvvv "Removing directory or file \`${1}'.";
+				rtl_log_msg vvvv "Removing directory or file \`${1}'.";
 				rm -rf -- "${1}"; _rc="${?}";
 			elif [ "${_op}" = source_opt ]\
-			&& ex_rtl_fileop test "${1}"\
+			&& rtl_fileop test "${1}"\
 			&& exp_rtl_fileop_check "${PREFIX}" "${1}"; then
-				ex_rtl_log_msg vvvv "Sourcing file \`${1}'.";
+				rtl_log_msg vvvv "Sourcing file \`${1}'.";
 				. "${1}"; _rc="${?}";
 			elif [ "${_op}" = test ]\
 			&& exp_rtl_fileop_check "${PREFIX}" "${1}"\
@@ -100,11 +100,11 @@ ex_rtl_fileop() {
 				return 1;
 			elif [ "${_op}" = touch ]\
 			&& exp_rtl_fileop_check "${PREFIX}" "${1}"; then
-				ex_rtl_log_msg vvvv "Touching file \`${1}'.";
+				rtl_log_msg vvvv "Touching file \`${1}'.";
 				touch -- "${1}"; _rc="${?}";
 			fi; shift;
 		done; ;;
-	*)	ex_rtl_log_msg failexit "Error: ex_rtl_fileop() called w/ invalid parameter(s): ${*}"; ;;
+	*)	rtl_log_msg failexit "Error: rtl_fileop() called w/ invalid parameter(s): ${*}"; ;;
 	esac; return "${_rc}";
 };
 
diff --git a/subr/ex_rtl_install.subr b/subr/rtl_install.subr
index 742347d7..a1c70a01 100644
--- a/subr/ex_rtl_install.subr
+++ b/subr/rtl_install.subr
@@ -2,7 +2,7 @@
 # set +o errexit -o noglob is assumed.
 #
 
-ex_rtl_install() {
+rtl_install() {
 	local _verbose="" _prefix="" _ln_target="" _ln_fname=""	\
 		_mkdir_fname="" _file_fname_src="" _file_fname_dst="";
 	if [ "${1}" = "-v" ]; then
@@ -18,16 +18,16 @@ ex_rtl_install() {
 			_ln_fname="${_prefix:+${_prefix}/}${_ln_fname}";
 		fi;
 		if [ -e "${_ln_fname}" ]; then
-			ex_rtl_fileop rm "${_ln_fname}";
+			rtl_fileop rm "${_ln_fname}";
 		fi;
-		ex_rtl_fileop ln_symbolic "${_ln_target}" "${_ln_fname}";
+		rtl_fileop ln_symbolic "${_ln_target}" "${_ln_fname}";
 		;;
 	/=*)
 		_mkdir_fname="${1#/=}";
 		if [ "${_mkdir_fname#/}" = "${_mkdir_fname}" ]; then
 			_mkdir_fname="${_prefix:+${_prefix}/}${_mkdir_fname}";
 		fi;
-		ex_rtl_fileop mkdir "${_mkdir_fname}";
+		rtl_fileop mkdir "${_mkdir_fname}";
 		;;
 	*)
 		_file_fname_src="${1%=*}";
@@ -38,7 +38,7 @@ ex_rtl_install() {
 		if [ "${_file_fname_dst#/}" = "${_file_fname_dst}" ]; then
 			_file_fname_dst="${_prefix:+${_prefix}/}${_file_fname_dst}";
 		fi;
-		ex_rtl_fileop cp "${_file_fname_src}" "${_file_fname_dst}";
+		rtl_fileop cp "${_file_fname_src}" "${_file_fname_dst}";
 		;;
 	esac; shift;
 	done;
diff --git a/subr/ex_rtl_list.subr b/subr/rtl_list.subr
index fb2bde72..056d8016 100644
--- a/subr/ex_rtl_list.subr
+++ b/subr/rtl_list.subr
@@ -2,7 +2,7 @@
 # set +o errexit -o noglob is assumed.
 #
 
-ex_rtl_lconcat() {
+rtl_lconcat() {
 	local _list="${1}" _litem_new="${2}" _sep="${3:- }" IFS="${3:-${IFS}}";
 	if [ -n "${_list}" ]; then
 		printf "%s%s%s" "${_list}" "${_sep}" "${_litem_new}";
@@ -11,7 +11,7 @@ ex_rtl_lconcat() {
 	fi;
 };
 
-ex_rtl_lfilter() {
+rtl_lfilter() {
 	local	_list="${1}" _filter="${2}" _sep="${3:- }" IFS="${3:-${IFS}}"	\
 		_filterfl="" _litem="" _litem_filter="" _lnew="";
 	if [ -z "${_filter}" ]; then
@@ -30,7 +30,7 @@ ex_rtl_lfilter() {
 	echo "${_lnew}";
 };
 
-ex_rtl_llength() {
+rtl_llength() {
 	local _list="${1}" _sep="${2:- }" IFS="${2:-${IFS}}" _litem="" _llength=0;
 	for _litem in ${_list}; do
 		: $((_llength+=1));
@@ -38,12 +38,12 @@ ex_rtl_llength() {
 	echo "${_llength}";
 };
 
-ex_rtl_lmatch() {
+rtl_lmatch() {
 	local _list="${1}" _item="${2}" _sep="${3}";
-	[ -n "$(ex_rtl_lsearch "${_list}" "${_item}" "${_sep}")" ];
+	[ -n "$(rtl_lsearch "${_list}" "${_item}" "${_sep}")" ];
 };
 
-ex_rtl_lsearch() {
+rtl_lsearch() {
 	local	_list="${1}" _filter="${2}" _sep="${3:- }" IFS="${3:-${IFS}}"	\
 		_litem="" _litem_filter="" _lnew="";
 	if [ -z "${_filter}" ]; then
@@ -59,15 +59,15 @@ ex_rtl_lsearch() {
 	echo "${_lnew}";
 };
 
-ex_rtl_lunfold_depends() {
+rtl_lunfold_depends() {
 	local _vname_template="${1}" _depends="" _name="" _names=""; shift;
 	for _name in "${@}"; do
-		if _depends="$(ex_rtl_get_var_unsafe -u "$(eval printf \"%s\" \""${_vname_template}"\")")"\
+		if _depends="$(rtl_get_var_unsafe -u "$(eval printf \"%s\" \""${_vname_template}"\")")"\
 		&& [ -n "${_depends}" ]; then
-			_depends="$(ex_rtl_lunfold_depends "${_vname_template}" ${_depends})";
-			_names="$(ex_rtl_lconcat "${_names}" "${_depends}")";
+			_depends="$(rtl_lunfold_depends "${_vname_template}" ${_depends})";
+			_names="$(rtl_lconcat "${_names}" "${_depends}")";
 		fi;
-		_names="$(ex_rtl_lconcat "${_names}" "${_name}")";
+		_names="$(rtl_lconcat "${_names}" "${_name}")";
 	done;
 	echo "${_names}";
 };
diff --git a/subr/ex_rtl_log.subr b/subr/rtl_log.subr
index 514d4636..e27e81d6 100644
--- a/subr/ex_rtl_log.subr
+++ b/subr/rtl_log.subr
@@ -23,9 +23,9 @@ exp_rtl_log_printf() {
 	printf "\033[0m\033[${_attr}m%s\033[0m\n" "${_msg}";
 };
 
-ex_rtl_log_env_vars() {
+rtl_log_env_vars() {
 	local _nvar=1 _arg="" _arg_len_max=0;
-	ex_rtl_log_msg info "Variables for this ${1:-build}:"; shift;
+	rtl_log_msg info "Variables for this ${1:-build}:"; shift;
 	while [ ${_nvar} -le ${#} ]; do
 		_arg="$(eval echo \${${_nvar}})";
 		_arg="${_arg%%=*}";
@@ -34,18 +34,18 @@ ex_rtl_log_env_vars() {
 		fi; : $((_nvar+=1));
 	done;
 	while [ ${#} -gt 0 ]; do
-		ex_rtl_log_msg info "$(printf			\
+		rtl_log_msg info "$(printf			\
 			"%${_arg_len_max}.${_arg_len_max}s=%s"	\
-			"${1%%=*}" "$(ex_rtl_get_var_unsafe ${1#*=})")";
+			"${1%%=*}" "$(rtl_get_var_unsafe ${1#*=})")";
 		shift;
 	done;
 };
 
-ex_rtl_log_set_vnfo_lvl() {
+rtl_log_set_vnfo_lvl() {
 	EXP_RTL_LOG_VNFO_LVL="${1}";
 };
 
-ex_rtl_log_msg() {
+rtl_log_msg() {
 	local _lvl="${1}" _lvl_uc="" _attr=""; shift;
 	if [ "${_lvl}" = vnfo ]\
 	|| [ "${_lvl}" = vucc ]\
@@ -61,12 +61,12 @@ ex_rtl_log_msg() {
 	&& [ "${EXP_RTL_LOG_VNFO_LVL:-0}" -lt 4 ]; then
 		return;
 	fi;
-	_lvl_uc="$(ex_rtl_toupper "${_lvl%exit}")";
-	_attr="$(ex_rtl_get_var_unsafe "DEFAULT_LOG_MSG_${_lvl_uc}_COLOUR")";
+	_lvl_uc="$(rtl_toupper "${_lvl%exit}")";
+	_attr="$(rtl_get_var_unsafe "DEFAULT_LOG_MSG_${_lvl_uc}_COLOUR")";
 	if [ ${#} -gt 1 ]; then
-		exp_rtl_log_printf "${_attrs}" "==> %s %s %s" "$(ex_rtl_date)" "${1}" "$*";
+		exp_rtl_log_printf "${_attrs}" "==> %s %s %s" "$(rtl_date)" "${1}" "$*";
 	else
-		exp_rtl_log_printf "${_attrs}" "==> %s %s" "$(ex_rtl_date)" "${1}";
+		exp_rtl_log_printf "${_attrs}" "==> %s %s" "$(rtl_date)" "${1}";
 	fi;
 	if [ ${_lvl} = failexit ]; then
 		exit 1;
diff --git a/subr/ex_rtl_state.subr b/subr/rtl_state.subr
index 406da477..1ee8258b 100644
--- a/subr/ex_rtl_state.subr
+++ b/subr/rtl_state.subr
@@ -2,38 +2,38 @@
 # set +o errexit -o noglob is assumed.
 #
 
-ex_rtl_state_clear() {
+rtl_state_clear() {
 	local _workdir="${1}" _pkg_name="${2}" _pkg_fname="";
 	for _pkg_fname in $(find "${_workdir}"				\
 			-maxdepth 1 -mindepth 1 -name .${_pkg_name}.\* -type f); do
-		ex_rtl_fileop rm "${_pkg_fname}";
+		rtl_fileop rm "${_pkg_fname}";
 	done;
 };
 
-ex_rtl_state_set() {
+rtl_state_set() {
 	local _workdir="${1}" _pkg_fname="${2}" _done_fname_pfx="";
 	_done_fname_pfx="${_workdir}/.${_pkg_fname}";
 	shift 2; while [ ${#} -ge 1 ]; do
 		if [ -z "${1}" ]; then
 			shift; continue;
 		elif [ "${1#-}" != "${1}" ]; then
-			ex_rtl_fileop rm "${_done_fname_pfx}.${1#-}";
+			rtl_fileop rm "${_done_fname_pfx}.${1#-}";
 		else
-			ex_rtl_fileop touch "${_done_fname_pfx}.${1}";
+			rtl_fileop touch "${_done_fname_pfx}.${1}";
 		fi;
 	shift; done;
 };
 
-ex_rtl_state_test() {
+rtl_state_test() {
 	local _workdir="${1}" _pkg_name="${2}" _build_step="${3}"	\
 		_restart_at="${4}" _done_fname="";
 	_done_fname="${_workdir}/.${_pkg_name}.${_build_step}";
 	if [ -z "${_restart_at}" ]; then
-		ex_rtl_fileop test "${_done_fname}";
+		rtl_fileop test "${_done_fname}";
 	elif [ "${_restart_at}" = "ALL" ]; then
 		return 1;
 	else
-		! ex_rtl_lmatch "${_restart_at}" "${_build_step}" ",";
+		! rtl_lmatch "${_restart_at}" "${_build_step}" ",";
 	fi;
 };
 
diff --git a/subr/ex_rtl_string.subr b/subr/rtl_string.subr
index 9b8874fa..0e549d3c 100644
--- a/subr/ex_rtl_string.subr
+++ b/subr/rtl_string.subr
@@ -2,7 +2,17 @@
 # set +o errexit -o noglob is assumed.
 #
 
-ex_rtl_tolower() {
+rtl_isnumber() {
+	local _s="${1}" _rc=0;
+	while [ -n "${_s}" ]; do
+	case "${_s}" in
+	[0-9]*)	_s="${_s#[0-9]}"; ;;
+	*)	_rc=1; break; ;;
+	esac; done;
+	return "${_rc}";
+};
+
+rtl_tolower() {
 	local _s="${1}" _s_new="";
 	while [ -n "${_s}" ]; do
 	case "${_s}" in
@@ -41,7 +51,7 @@ ex_rtl_tolower() {
 	echo "${_s_new}";
 };
 
-ex_rtl_toupper() {
+rtl_toupper() {
 	local _s="${1}" _s_new="";
 	while [ -n "${_s}" ]; do
 	case "${_s}" in