diff --git a/makefiles/consts.mk b/makefiles/consts.mk
index 95d69a2..f1f717f 100644
--- a/makefiles/consts.mk
+++ b/makefiles/consts.mk
@@ -1,6 +1,6 @@
 # -*- makefile -*-
 # -----------------------------------------------------------------------
-# Copyright 2022 Open Networking Foundation (ONF) and the ONF Contributors
+# Copyright 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -14,30 +14,52 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-# SPDX-FileCopyrightText: 2022 Open Networking Foundation (ONF) and the ONF Contributors
+# SPDX-FileCopyrightText: 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
 # SPDX-License-Identifier: Apache-2.0
 # -----------------------------------------------------------------------
+# https://gerrit.opencord.org/plugins/gitiles/onf-make
+# ONF.makefile.version = 1.0
+# -----------------------------------------------------------------------
 
 $(if $(DEBUG),$(warning ENTER))
 
-null        :=#
-space       := $(null) $(null)
-dot         ?= .
+# include makefiles/constants.mk
+export dot          :=.
+export null         :=#
+export space        := $(null) $(null)
+export quote-single := $(null)'$(null)#'
+export quote-double := $(null)"$(null)#"
 
-HIDE        ?= @
+# [DEBUG] make {target} HIDE=
+HIDE           ?= @
 
-env-clean   = /usr/bin/env --ignore-environment
-xargs-n1    := xargs -0 -t -n1 --no-run-if-empty
+env-clean      ?= /usr/bin/env --ignore-environment
+
+xargs-cmd       := xargs -0 -t --no-run-if-empty
+xargs-n1        := $(xargs-cmd) -n1
+xargs-n1-clean  := $(env-clean) $(xargs-n1)
+xargs-cmd-clean := $(env-clean) $(xargs-cmd)
 
 ## -----------------------------------------------------------------------
-## Not recommended but support (-u)ndef-less shell for pyenv activate
-## TODO: declare a pyenv shell
+## Intent: NOP command for targets whose dependencies do all heavy lifting
 ## -----------------------------------------------------------------------
+## usage: foo bar tans
+## <tab>$(nop-command)
+## -----------------------------------------------------------------------
+nop-cmd        := :
+
+## -----------------------------------------------------------------------
+## Default shell:
+##   o set -e            enable error checking
+##   o set -u            report undefined errors
+##   o set -o pipefail   propogate shell pipeline failures.
+## -----------------------------------------------------------------------
+SHELL ?= /bin/bash
 have-shell-bash := $(filter bash,$(subst /,$(space),$(SHELL)))
 $(if $(have-shell-bash),$(null),\
-  $(eval export SHELL := /bin/bash -euo pipefail))
+  $(eval export SHELL := bash -euo pipefail))
 
-shell-pyenv := bash -eo pipefail
+export SHELL ?= bash -euo pipefail
 
 $(if $(DEBUG),$(warning LEAVE))