diff --git a/makefiles/consts.mk b/makefiles/consts.mk
index ce71862..c1306ac 100644
--- a/makefiles/consts.mk
+++ b/makefiles/consts.mk
@@ -13,25 +13,42 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+#
+# 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))
 
-##-------------------##
-##---]  GLOBALS  [---##
-##-------------------##
-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-n1       := xargs -0 -t -n1 --no-run-if-empty
+xargs-n1-clean := $(env-clean) $(xargs-n1)
 
+## -----------------------------------------------------------------------
+## 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))
+
+export SHELL ?= bash -euo pipefail
 
 $(if $(DEBUG),$(warning LEAVE))