Makefile edits to improve library lint target support.

Makefile
--------
  o Replace inlined includes with single $(MAKEDIR)/include.mk
  o virtualenv install w/dependencies handled by makefiles/virtualenv.mk
  o Use '&&' for command separation to improve error handling.
  o Added more target documentation.
  o Re-home doc8/rst syntax checking into makefiles/lint/doc8.mk.

howto/code/linting.rst
----------------------
  o Document supported lint targets on docs.voltha.org.

howto/release/index.rst
howto/release/post-release/
howto/release/vcs/
---------------------------
  o Document more release related activity (bugfix branch creation)

makefiles/consts.mk
-------------------
  o Define and use more library macros.

config.mk
---------
  o Per-repository library makefile configuration, disable linting.

makefiles/virtualenv.mk
-----------------------
  o Library virtualenv install with dependences.
  o Begin using a consistent install directory.
  o Ugh: repository (voltha-docs) submodules each install a full venv.
  o Install dependency drive based on existence of activate script.
  o Lint targets updated to use activate script as a dependency.
  o Update activate macro to run:  set -u && activate && set +u

makefiles/patches/include.mk
----------------------------
  o Update to use virtualenv.mk defined macros.

makefiles/lint/doc8.mk
makefiles/lint/python/flake8.mk
makefiles/lint/json.mk
makefiles/lint/python/pylint.mk
makefiles/lint/robot.mk
makefiles/lint/shell.mk
makefiles/lint/yaml.mk
-------------------------------
  o All library linting defines consistent targets and logic.
  o Support two library targets: lint-all and lint-modified.
  o Default to checking all available sources.
  o Linting can be disabled per-repository via {project}/config.mk

Change-Id: I7b7b5e523c867183d44244a0da21cfa3584e9a50
diff --git a/Makefile b/Makefile
index ba5bba0..0ae2243 100644
--- a/Makefile
+++ b/Makefile
@@ -26,10 +26,8 @@
 ##--------------------##
 ##---]  INCLUDES  [---##
 ##--------------------##
-include $(MAKEDIR)/consts.mk
-include $(MAKEDIR)/help/include.mk
-include $(MAKEDIR)/patches/include.mk
-include $(MAKEDIR)/help/variables.mk
+-include config.mk
+include $(MAKEDIR)/include.mk
 
 # You can set these variables from the command line.
 SPHINXOPTS   ?=
@@ -50,43 +48,17 @@
 # Static docs, built by other means (usually robot framework)
 STATIC_DOCS    := _static/voltha-system-tests _static/cord-tester
 
-# name of python virtualenv that is used to run commands
-VENV_NAME      := venv_docs
-
+# Why is existing source Makefile PHONY (?)
 .PHONY: help test lint reload Makefile prep
 
-# Put it first so that "make" without argument is like "make help".
-help :: $(VENV_NAME)
-	@ echo
-	@ source $</bin/activate ; set -u ;\
-	$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
-
-# -----------------------------------------------------------------------
-# Create the virtualenv with all the tools installed
-# -----------------------------------------------------------------------
-.PHONY: venv
-venv: $(VENV_NAME)
-
-$(VENV_NAME):
-	@echo
-	@echo "============================="
-	@echo "Installing python virtual env"
-	@echo "============================="
-	virtualenv -p python3 $@ ;\
-	source ./$@/bin/activate ;\
-	python -m pip install -r requirements.txt
-ifndef NO_PATCH
-	@echo
-	@echo "========================================"
-	@echo "Applying python virtualenv patches as needed (v3.10+)"
-	@echo "========================================"
-	./patches/python_310_migration.sh '--venv' "$@" 'apply'
-endif
-
-# automatically reload changes in browser as they're made
-reload: $(VENV_NAME)
-	source $</bin/activate ; set -u ;\
-	sphinx-reload $(SOURCEDIR)
+## -----------------------------------------------------------------------
+## Intent: Real time viewing, dynamically generate and reload document
+##         changes for web browser viewing.
+## Usage:
+##   make reload
+## -----------------------------------------------------------------------
+reload: $(venv-activate-script)
+	$(activate) && sphinx-reload $(SOURCEDIR)
 
 ## -----------------------------------------------------------------------
 ## Intent: lint and link verification. linkcheck is part of sphinx
@@ -95,6 +67,7 @@
 
 ## -----------------------------------------------------------------------
 ## Intent: Exercise all generation targets
+## Bridge: library workaround to support legacy targets
 ## -----------------------------------------------------------------------
 test-all-targets += html
 test-all-targets += coverage
@@ -104,22 +77,13 @@
 test-all-targe4ts += text
 # test-all-targets += latex
 
-
 test-all : test
 	$(MAKE) $(test-all-targets)
 
 # doctest
 # coverage
 # linkcheck
-lint: doc8
-# include $(MAKEDIR)/lint/shell.mk
 
-doc8: $(VENV_NAME) | $(OTHER_REPO_DOCS)
-	source $</bin/activate ; set -u ;\
-	doc8 --max-line-length 119 \
-	     $$(find . -name \*.rst ! -path "*venv*" ! -path "*vendor*" ! -path "*repos*" )
-
-# markdown linting
 #  currently not enabled, should be added to lint target
 LINT_STYLE ?= mdl_strict.rb
 md-lint: | $(OTHER_REPO_DOCS)
@@ -128,14 +92,14 @@
 	@echo "---"
 	@cat $(LINT_STYLE)
 	@echo "---"
-	mdl -s $(LINT_STYLE) `find -L $(SOURCEDIR) ! -path "./_$(VENV_NAME)/*" ! -path "./_build/*" ! -path "./repos/*" ! -path "*vendor*" -name "*.md"`
+	mdl -s $(LINT_STYLE) `find -L $(SOURCEDIR) ! -path "./_$(venv-activate-script)/*" ! -path "./_build/*" ! -path "./repos/*" ! -path "*vendor*" -name "*.md"`
 
 # clean up
 clean:
 	$(RM) -r $(BUILDDIR) $(OTHER_REPO_DOCS) $(STATIC_DOCS)
 
-clean-all sterile: clean
-	$(RM) -r $(VENV_NAME) repos
+clean-all sterile :: clean
+	$(RM) -r $(venv-activate-script) repos
 
 # checkout the repos inside repos/ dir
 repos:
@@ -157,8 +121,10 @@
 	  then git clone $(REPO_HOST)/$(@F) $@ ;\
 	fi
 
-# checkout correct ref if not under test, then copy subdirectories into main
-# docs dir
+## -----------------------------------------------------------------------
+## Intent: checkout correct ref if not under test, then copy
+##         subdirectories into main docs dir
+## -----------------------------------------------------------------------
 $(OTHER_REPO_DOCS): | $(CHECKOUT_REPOS)
 	if [ "$(SKIP_CHECKOUT)" != "$@" ] ;\
 	  then GIT_REF=`grep '^$@ ' git_refs | awk '{print $$3}'` ;\
@@ -179,7 +145,9 @@
 	mkdir -p $@
 	cp -r cord-tester/gendocs/* $@
 
-# generate a list of git checksums suitable for updating git_refs
+## -----------------------------------------------------------------------
+## Intent: generate a list of git checksums suitable for updating git_refs
+## -----------------------------------------------------------------------
 freeze: repos
 	@for repo in $(OTHER_REPO_DOCS) ; do \
 	  GIT_SUBDIR=`grep "^$$repo " git_refs | awk '{print $$2}'` ;\
@@ -189,24 +157,29 @@
 	  cd ../.. ;\
 	done
 
-# build multiple versions
-multiversion: $(VENV_NAME) Makefile | prep $(OTHER_REPO_DOCS)
-	source $</bin/activate ; set -u ;\
-	sphinx-multiversion "$(SOURCEDIR)" "$(BUILDDIR)/multiversion" $(SPHINXOPTS)
+## -----------------------------------------------------------------------
+## Intent: build multiple versions
+## -----------------------------------------------------------------------
+multiversion: $(venv-activate-script) Makefile | prep $(OTHER_REPO_DOCS)
+	$(activate)\
+ && sphinx-multiversion "$(SOURCEDIR)" "$(BUILDDIR)/multiversion" $(SPHINXOPTS)
 	cp "$(SOURCEDIR)/_templates/meta_refresh.html" "$(BUILDDIR)/multiversion/index.html"
 
-# prep target - used in sphinx-multiversion to properly link
+## -----------------------------------------------------------------------
+## Intent: used in sphinx-multiversion to properly link
+## -----------------------------------------------------------------------
 prep: | $(OTHER_REPO_DOCS) $(STATIC_DOCS)
 
-# Catch-all target: route all unknown targets to Sphinx using the new
-# "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
-# %: $(VENV_NAME) Makefile | $(OTHER_REPO_DOCS) $(STATIC_DOCS)
-
+## -----------------------------------------------------------------------
+## Intent: Forward sphinx supported targets to sphinxbuild.
+## Bridge: legacy makefile wildcard rule forwarded unknown targets to sphinx.
+##         library makefiles do more so transfer control only when needed.
+## -----------------------------------------------------------------------
 include $(MAKEDIR)/voltha/docs-catchall-targets.mk
-$(voltha-docs-catchall): $(VENV_NAME) Makefile | $(OTHER_REPO_DOCS) $(STATIC_DOCS)
+$(voltha-docs-catchall): $(venv-activate-script) Makefile | $(OTHER_REPO_DOCS) $(STATIC_DOCS)
 	@echo " ** CATCHALL: $@"
-	source $</bin/activate ; set -u ;\
-	$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
+	$(activate)\
+ && $(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
 
 ## -----------------------------------------------------------------------
 ## -----------------------------------------------------------------------
@@ -215,6 +188,15 @@
 	"$(BROWSER)" _build/html/index.html
 
 ## -----------------------------------------------------------------------
+## Intent: Display makefile target help
+## -----------------------------------------------------------------------
+help :: $(venv-activate-script)
+	@ echo
+	$(HIDE)$(activate) \
+ && $(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
+
+## -----------------------------------------------------------------------
+## Intent: Display make hel footer
 ## -----------------------------------------------------------------------
 include $(MAKEDIR)/help/trailer.mk
 
diff --git a/VERSION b/VERSION
index 6ceb272..c7e0a98 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.11.1
+2.11.1-dev1
diff --git a/config.mk b/config.mk
new file mode 100644
index 0000000..2add84e
--- /dev/null
+++ b/config.mk
@@ -0,0 +1,45 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 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.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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.
+# -----------------------------------------------------------------------
+
+##---------------------------------------##
+##---]  Disable lint targets by name [---##
+##---------------------------------------##
+# NO-LINT-DOC8       := true
+NO-LINT-FLAKE8       := true#      # NOTE[1]
+# NO-LINT-JJB        := true
+NO-LINT-JSON       := true
+#   python -m json.tool ./_build/linkcheck/output.json
+#   Extra data: line 2 column 1 (char 181)
+# NO-LINT-MAKE       := true
+NO-LINT-PYLINT       := true#      # NOTE[1]
+# NO-LINT-PYTHON     := true
+NO-LINT-ROBOT      := true#        # NOTE[2]
+# NO-LINT-SHELL      := true
+# NO-LINT-TOX        := true#      # WIP
+# NO-LINT-YAML       := true
+
+# NOTE[1] - Cleanup needed to enable as a default make lint target
+# NOTE[2] - Doc repo, no need to lint robot sources here.
+
+##-----------------------------##
+##---]  Custom exclusions  [---##
+##-----------------------------##
+lint-doc8-excl += --ignore-path "vendor"
+
+config-mk-version    := 1.0
+
+# [EOF]
diff --git a/howto/code/linting.rst b/howto/code/linting.rst
index cc837f7..9550d54 100644
--- a/howto/code/linting.rst
+++ b/howto/code/linting.rst
@@ -11,15 +11,19 @@
 
     make help | grep lint
     lint-chart                    chart_version_check.sh
+    lint-doc8                     Syntax check *.rst documentation files.
     lint-helm                     Syntax check helm configs
     lint-json                     Syntax check json sources
     lint-license                  Verify sources contain a license block.
-    lint-python                   Syntax check using pylint and flake8
     lint-robot                    Syntax check robot sources using rflint
     lint-shell                    Syntax check bash,bourne,etc sources
     lint-yaml                     Syntax check yaml source using yamllint
     UNSTABLE=                     Build targets prone to failure (lint-helm)
 
+    [PYTHON]
+    lint-flake8                   Syntax check using pylint and flake8
+    lint-pylint                   Syntax check using pylint and flake8
+
 |
 
 
@@ -51,6 +55,57 @@
 |
 
 
+doc8 / RST files
+++++++++++++++++
+
+Command: `doc8 <https://pypi.org/project/doc8/>`_
+
+.. code:: bash
+
+    make clean
+    make lint                2>&1 | tee log
+    make lint-doc8-all      2>&1 | tee log
+    make lint-doc8-modified 2>&1 | tee log
+
+Sources:
+
+- `makefiles/lint <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/makefiles/lint/>`__
+- makefiles/lint/doc8.mk
+
+Notes:
+
+- lint-doc8-all target dependency will create a `python virtual env <https://wiki.opennetworking.org/display/JOEY/PythonVenv>`_
+- python 3.10+ requires `virtual env patching <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/patches/>`_ (dynamic, applied when needed).
+- `makefiles/patches/include.mk <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/makefiles/patches/>`_
+
+|
+
+
+python: flake8
+++++++++++++++
+
+Command: `flake8 <https://flake8.pycqa.org/en/latest>`_
+
+.. code:: bash
+
+    make clean
+    make lint                 2>&1 | tee log
+    make lint-flake8-all      2>&1 | tee log
+    make lint-flake8-modified 2>&1 | tee log
+
+Sources:
+
+- `makefiles/lint <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/makefiles/lint/>`__
+- makefiles/lint/flake8.mk
+
+Notes:
+
+- lint-flake8-all target dependency will create a `python virtual env <https://wiki.opennetworking.org/display/JOEY/PythonVenv>`_
+- python 3.10+ requires `virtual env patching <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/patches/>`_ (dynamic, applied when needed).
+- `makefiles/patches/include.mk <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/makefiles/patches/>`_
+
+|
+
 Helm Charts
 +++++++++++
 
@@ -86,13 +141,14 @@
 JSON
 ++++
 
-Command:
-- `json.tool <https://docs.python.org/3/library/json.html>`_
+Command: `json.tool <https://docs.python.org/3/library/json.html>`_
 
 .. code:: bash
 
     make clean
-    make lint-json 2>&1 | tee log
+    make lint               2>&1 | tee log
+    make lint-json-all      2>&1 | tee log
+    make lint-json-modified 2>&1 | tee log
 
 Sources:
 
@@ -120,28 +176,28 @@
 |
 
 
-python
-++++++
+python: pylint
+++++++++++++++
 
-Command:
-- `flake8 <https://flake8.pycqa.org/en/latest>`_
-- `pylint <https://www.pylint.org/>`_
+Command: `pylint <https://www.pylint.org/>`_
 
 .. code:: bash
 
     make clean
-    make lint-python 2>&1 | tee log
+    make lint                 2>&1 | tee log
+    make lint-pylint-all      2>&1 | tee log
+    make lint-pylint-modified 2>&1 | tee log
 
 Sources:
 
 - `makefiles/lint <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/makefiles/lint/>`__
-- `makefiles/lint/python.mk <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/makefiles/lint/python.mk>`_
+- makefiles/lint/pylint.mk
 - `makefiles/patches/include.mk <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/makefiles/patches/>`_
 
 Notes:
 
 - pylint the --py3k option is no longer supported by v3.10+
-- lint-python target dependency will create a `python virtual env <https://wiki.opennetworking.org/display/JOEY/PythonVenv>`_
+- lint-pylint-all target dependency will create a `python virtual env <https://wiki.opennetworking.org/display/JOEY/PythonVenv>`_
 - python 3.10+ requires `virtual env patching <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/patches/>`_ (dynamic, applied when needed).
 
 |
@@ -150,12 +206,19 @@
 Robot
 +++++
 
-Command: rflint
+Command: rflint `robotframework-lint <https://pypi.org/project/robotframework-lint/>`_
+
+.. code:: bash
+
+    make clean
+    make lint                2>&1 | tee log
+    make lint-robot-all      2>&1 | tee log
+    make lint-robot-modified 2>&1 | tee log
 
 Sources:
 
 - `makefiles/lint <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/makefiles/lint/>`__
-- `makefiles/lint/robot.mk <https://gerrit.opencord.org/plugins/gitiles/voltha-system-tests/+/refs/heads/master/makefiles/lint/robot.mk>`_
+- `makefiles/lint/robot.mk <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/makefiles/lint/robot.mk>`_
 
 |
 
@@ -178,10 +241,17 @@
 
 Command: `shellcheck <https://github.com/koalaman/shellcheck>`_
 
+.. code:: bash
+
+    make clean
+    make lint                2>&1 | tee log
+    make lint-shell-all      2>&1 | tee log
+    make lint-shell-modified 2>&1 | tee log
+
 Sources:
 
 - `makefiles/lint <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/makefiles/lint/>`__
-- `makefiles/lint/shell.mk <https://gerrit.opencord.org/plugins/gitiles/voltha-system-tests/+/refs/heads/master/makefiles/lint/shell.mk>`_
+- `makefiles/lint/shell.mk <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/makefiles/lint/shell.mk>`_
 
 |
 
@@ -189,17 +259,19 @@
 Yaml
 ++++
 
-Command: yamllint
+Command: `yamllint <https://yamllint.readthedocs.io/en/stable/>`_
 
 .. code:: bash
 
     make clean
-    make lint-yaml 2>&1 | tee log
+    make lint           2>&1 | tee log
+    make lint-yaml-all  2>&1 | tee log
+    make lint--modified 2>&1 | tee log
 
 Sources:
 
 - `makefiles/lint <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/makefiles/lint/>`__
-- `makefiles/lint/yaml.mk <https://gerrit.opencord.org/plugins/gitiles/voltha-system-tests/+/refs/heads/master/makefiles/lint/yaml.mk>`_
+- `makefiles/lint/yaml.mk <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master/makefiles/lint/yaml.mk>`_
 
 |
 
@@ -222,7 +294,7 @@
 - [`master <https://gerrit.opencord.org/plugins/gitiles/pod-configs/+/refs/heads/master>`__] `pod-configs <https://gerrit.opencord.org/plugins/gitiles/pod-configs>`_
 - [`master <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master>`__] `voltha-docs <https://gerrit.opencord.org/plugins/gitiles/voltha-docs>`_
 - [`master <https://gerrit.opencord.org/plugins/gitiles/voltha-helm-charts/+/refs/heads/master>`__] `voltha-helm-charts <https://gerrit.opencord.org/plugins/gitiles/voltha-helm-charts>`_
-- [`master <https://gerrit.opencord.org/plugins/gitiles/voltha-system-tests/+/refs/heads/master>`__] `voltha-system-tests <https://gerrit.opencord.org/plugins/gitiles/voltha-system-tests>`_
+- [`master <https://gerrit.opencord.org/plugins/gitiles/voltha-docs/+/refs/heads/master>`__] `voltha-docs <https://gerrit.opencord.org/plugins/gitiles/voltha-docs>`_
 
 |
 
@@ -230,8 +302,11 @@
 Notes
 ~~~~~
 
-- Make lint complaints are not necessarily fatal.
 - Volume problem reports require cleanup before linting can become a default.
+
+  - After bulk linting problems for a language source have been cleaned up
+    default linting can be enabled by modifing {project-root}/config.mk.
+
 - Lint target support is globally available across repositories, given time
   it will be.  Submit patches as needed or open a jira ticket to request
   linting support in specific repositories.
diff --git a/howto/release/index.rst b/howto/release/index.rst
index e4178cb..39d5cf5 100644
--- a/howto/release/index.rst
+++ b/howto/release/index.rst
@@ -7,6 +7,7 @@
    components/index
    hierarchy/index
    voltha-docs/index
+   post-release/index
 
    voltctl/index
    voltctl/install
diff --git a/howto/release/post-release/gitreview.rst b/howto/release/post-release/gitreview.rst
new file mode 100644
index 0000000..7bebb82
--- /dev/null
+++ b/howto/release/post-release/gitreview.rst
@@ -0,0 +1,30 @@
+gitreview branch update
+-----------------------
+
+After a release has been created and repositories have been branched & tagged:
+
+- voltha-helm-charts
+- voltha-system-tests
+
+Update the .gitreview file on the voltha-x.y release branch so commits are
+directed to branch=voltha-x.y rather than the default voltha=master
+
+.. code-block::
+   :emphasize-lines: 6
+
+   [gerrit]
+   host=gerrit.opencord.org
+   port=29418
+   project=voltha-helm-charts.git
+   defaultremote=origin
+   defaultbranch=master
+
+.. code-block::
+   :emphasize-lines: 6
+
+   [gerrit]
+   host=gerrit.opencord.org
+   port=29418
+   project=voltha-helm-charts.git
+   defaultremote=origin
+   defaultbranch=voltha-2.11
diff --git a/howto/release/post-release/index.rst b/howto/release/post-release/index.rst
new file mode 100644
index 0000000..3aadb95
--- /dev/null
+++ b/howto/release/post-release/index.rst
@@ -0,0 +1,9 @@
+VOLTHA Post Release Tasks
+=========================
+
+.. toctree::
+   :maxddepth 1
+
+   gitreview
+
+- Deprecated code marked for release (v2.6, v2.8 after v2.11) can be removed.
diff --git a/howto/release/vcs/notes b/howto/release/vcs/notes
new file mode 100644
index 0000000..4a7ef94
--- /dev/null
+++ b/howto/release/vcs/notes
@@ -0,0 +1,12 @@
+voltha-helm-charts
+voltha-system-tests
+  branch[1]: voltha-2.11
+     tag[2]: 2.11.0
+  update[3]: .gitreview
+  
+
+voltha-openolt-adapter
+voltha-openonu-adapter
+  1) git tag -a "Release tagging" v2.11.0          # (golang format: v + {revision})
+  
+  branch[2]: voltha-2.11
diff --git a/makefiles/consts.mk b/makefiles/consts.mk
index 043ec65..bac4362 100644
--- a/makefiles/consts.mk
+++ b/makefiles/consts.mk
@@ -13,16 +13,40 @@
 # 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
 # -----------------------------------------------------------------------
 
-null         :=#
-space        :=$(null) $(null)
-dot          :=.
-HIDE         ?=@
+$(if $(DEBUG),$(warning ENTER))
 
-# use bash for pusdh/popd and quick failures.
-# virtual env(s) activate has undefined vars so no -u
-#   ^---+ verify this is still true
-export SHELL := bash -e -o pipefail
+# include makefiles/constants.mk
+export dot          :=.
+export null         :=#
+export space        := $(null) $(null)
+export quote-single := $(null)"$(null)#"
+export quote-double := $(null)'$(null)#'
+
+# [DEBUG] make {target} HIDE=
+HIDE        ?= @
+
+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),\
+  $(eval export SHELL := bash -euo pipefail))
+
+export SHELL ?= bash -euo pipefail
+
+$(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]
diff --git a/makefiles/include.mk b/makefiles/include.mk
new file mode 100644
index 0000000..3042488
--- /dev/null
+++ b/makefiles/include.mk
@@ -0,0 +1,41 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# 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.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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 Open Networking Foundation (ONF) and the ONF Contributors
+# SPDX-License-Identifier: Apache-2.0
+# -----------------------------------------------------------------------
+
+$(if $(DEBUG),$(warning ENTER))
+
+# OPT_ROOT    ?= /opt/trainlab/current
+# OPT_MAKEDIR := $(OPT_ROOT)/makefiles
+# MAKEDIR     ?= $(OPT_MAKEDIR)
+
+ONF_MAKE ?= $(MAKEDIR)# [TODO] -- local and library makefiles/ needed.
+ONF_MAKE ?= $(error ONF_MAKE= is required)
+
+include $(ONF_MAKE)/consts.mk
+include $(ONF_MAKE)/help/include.mk
+
+include $(ONF_MAKE)/virtualenv.mk#        # lint-{jjb,python} depends on venv
+include $(ONF_MAKE)/lint/include.mk
+include $(ONF_MAKE)/todo.mk
+include $(MAKEDIR)/patches/include.mk#    # Patch when python 3.10+ in use
+include $(ONF_MAKE)/help/variables.mk
+
+$(if $(DEBUG),$(warning LEAVE))
+
+# [EOF]
diff --git a/makefiles/lint/doc8.mk b/makefiles/lint/doc8.mk
new file mode 100644
index 0000000..e0594df
--- /dev/null
+++ b/makefiles/lint/doc8.mk
@@ -0,0 +1,79 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 2017-2022 Open Networking Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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.
+# -----------------------------------------------------------------------
+
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-doc8 lint-doc8-all lint-doc8-modified
+
+have-rst-files := $(if $(strip $(RST_SOURCE)),true)
+RST_SOURCE     ?= $(error RST_SOURCE= is required)
+
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
+ifndef NO-LINT-DOC8
+  lint-doc8-mode := $(if $(have-doc8-files),modified,all)
+  lint : lint-doc8-$(lint-doc8-mode)
+endif# NO-LINT-DOC8
+
+# Consistent targets across lint makefiles
+lint-doc8-all      : lint-doc8
+lint-doc8-modified : lint-doc8
+
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
+lint-doc8-excl += --ignore-path '$(venv-name)'
+lint-doc8-excl += --ignore-path '$(BUILDDIR)'
+
+# YUCK! -- overhead
+#   o Submodule(s) use individual/variant virtualenv install paths.
+#   o Exclude special snowflakes to enable library makefile use.
+#   o [TODO] Use makefiles/virtualenv.mk to avoid duplication.
+
+lint-doc8-excl += --ignore-path '*/venv_cord'
+lint-doc8-excl += --ignore-path '*/vst_venv'
+
+lint-doc8-excl += --ignore-path './cord-tester'
+lint-doc8-excl += --ignore-path './repos/cord-tester'
+
+lint-doc8-excl += --ignore-path './bbsim/internal/bbsim/responders/sadis/dp.txt'
+lint-doc8-excl += --ignore-path './repos/bbsim/internal/bbsim/responders/sadis/dp.txt'
+lint-doc8-excl += --ignore-path './repos/voltha-helm-charts/voltha-infra/templates/NOTES.txt'
+lint-doc8-excl += --ignore-path './voltha-helm-charts/voltha-infra/templates/NOTES.txt'
+
+lint-doc8-args += --max-line-length 120
+
+lint-doc8: $(venv-activate-script)
+	@echo
+	@echo '** -----------------------------------------------------------------------'
+	@echo '** doc8 *.rst syntax checking'
+	@echo '** -----------------------------------------------------------------------'
+	$(activate) && doc8 --version
+	@echo
+	$(activate) && doc8 $(lint-doc8-excl) $(lint-doc8-args) .
+
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
+help::
+	@echo '  lint-doc8          Syntax check python using the doc8 command'
+  ifdef VERBOSE
+	@echo '  lint-doc8-all       doc8 checking: exhaustive'
+	@echo '  lint-doc8-modified  doc8 checking: only modified'
+  endif
+
+# [EOF]
diff --git a/makefiles/lint/include.mk b/makefiles/lint/include.mk
index 0f653c9..96f6bce 100644
--- a/makefiles/lint/include.mk
+++ b/makefiles/lint/include.mk
@@ -15,12 +15,29 @@
 # limitations under the License.
 # -----------------------------------------------------------------------
 
+# -----------------------------------------------------------------------
+# Intent: Display help banner early before library lint help targets.
+# -----------------------------------------------------------------------
 help::
 	@echo
 	@echo "[LINT]"
 
+## Disable python linting in bulk ?
+ifdef NO-LINT-PYTHON
+  NO-LINT-FLAKE8 := true
+  NO-LINT-PYLINT := true
+endif
+
+# Define early else {flake8,pylint}.mk will complain:
+#    PYTHON_FILES ?= $(error)
+have-python-files := $(if $(strip $(PYTHON_FILES)),true)
+
+##--------------------##
+##---]  INCLUDES  [---##
+##--------------------##
+include $(MAKEDIR)/lint/doc8.mk
 include $(MAKEDIR)/lint/json.mk
-include $(MAKEDIR)/lint/python.mk
+include $(MAKEDIR)/lint/python/include.mk
 include $(MAKEDIR)/lint/robot.mk
 include $(MAKEDIR)/lint/shell.mk
 include $(MAKEDIR)/lint/yaml.mk
diff --git a/makefiles/lint/json.mk b/makefiles/lint/json.mk
index e67fee1..1deeaba 100644
--- a/makefiles/lint/json.mk
+++ b/makefiles/lint/json.mk
@@ -1,8 +1,8 @@
 # -*- makefile -*-
 # -----------------------------------------------------------------------
-# Copyright 2017-2023 Open Networking Foundation
+# Copyright 2017-2023 Open Networking Foundation (ONF) and the ONF Contributors
 #
-# Licensed under the Apache License, Version 2.0 (the "License");
+# Licensed under the Apache License, Version 2.0 (the "License")
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
@@ -15,21 +15,78 @@
 # limitations under the License.
 # -----------------------------------------------------------------------
 
-JSON_FILES ?= $(error JSON_FILES= is rqeuired)
+$(if $(DEBUG),$(warning ENTER))
 
-.PHONY: lint-json
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-json lint-json-all lint-json-modified
 
-lint : lint-json
+have-json-files := $(if $(strip $(JSON_FILES)),true)
+JSON_FILES      ?= $(error JSON_FILES= required)
 
-lint-json: vst_venv
-	source ./$</bin/activate \
-	    ; set -u \
-	    ; for jsonfile in $(JSON_FILES); do \
-		echo "Validating json file: $$jsonfile" ;\
-		python -m json.tool $$jsonfile > /dev/null ;\
-	done
+## -----------------------------------------------------------------------
+## Intent: Use the json command to perform syntax checking.
+##   o If UNSTABLE=1 syntax check all sources
+##   o else only check sources modified by the developer.
+## Usage:
+##   % make lint UNSTABLE=1
+##   % make lint-json-all
+## -----------------------------------------------------------------------
+ifndef NO-LINT-JSON
+  lint-json-mode := $(if $(have-json-files),modified,all)
+  lint : lint-json-$(lint-json-mode)
+endif# NO-LINT-JSON
 
+## -----------------------------------------------------------------------
+## Intent: exhaustive json syntax checking
+## -----------------------------------------------------------------------
+json-find-args := $(null)
+json-find-args += -name '$(venv-name)'
+lint-json-all:	
+	$(HIDE)$(MAKE) --no-print-directory lint-json-install
+
+	$(activate)\
+ && find . \( $(json-find-args) \) -prune -o -name '*.json' -print0 \
+	| $(xargs-n1) python -m json.tool > /dev/null ;\
+
+## -----------------------------------------------------------------------
+## Intent: check deps for format and python3 cleanliness
+## Note:
+##   json --py3k option no longer supported
+## -----------------------------------------------------------------------
+lint-json-modified: $(venv-activate-script)
+	$(HIDE)$(MAKE) --no-print-directory lint-json-install
+
+	$(activate)\
+ && for jsonfile in $(JSON_FILES); do \
+        echo "Validating json file: $$jsonfile" ;\
+        python -m json.tool $$jsonfile > /dev/null ;\
+    done
+
+## -----------------------------------------------------------------------
+## Intent:
+## -----------------------------------------------------------------------
+.PHONY: lint-json-install
+lint-json-install: $(venv-activate-script)
+	@echo
+	@echo "** -----------------------------------------------------------------------"
+	@echo "** json syntax checking"
+	@echo "** -----------------------------------------------------------------------"
+#	$(activate) && pip install --upgrade json.tool
+#       $(activate) && python -m json.tool --version (?-howto-?)
+	@echo
+
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
 help::
-	@echo "  lint-json            Syntax check json sources"
+	@echo '  lint-json          Syntax check python using the json command'
+  ifdef VERBOSE
+	@echo '  lint-json-all       json checking: exhaustive'
+	@echo '  lint-json-modified  json checking: only modified'
+  endif
+
+$(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]
diff --git a/makefiles/lint/python/flake8.mk b/makefiles/lint/python/flake8.mk
new file mode 100644
index 0000000..bb474a9
--- /dev/null
+++ b/makefiles/lint/python/flake8.mk
@@ -0,0 +1,85 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 2017-2023 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.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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.
+# -----------------------------------------------------------------------
+
+$(if $(DEBUG),$(warning ENTER))
+
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-flake8 lint-flake8-all lint-flake8-modified
+
+PYTHON_FILES      ?= $(error PYTHON_FILES= required)
+
+## -----------------------------------------------------------------------
+## Intent: Use the flake8 command to perform syntax checking.
+## Usage:
+##   % make lint
+##   % make lint-flake8-all
+## -----------------------------------------------------------------------
+ifndef NO-LINT-FLAKE8
+  lint-flake8-mode := $(if $(have-python-files),modified,all)
+  lint : lint-flake8-$(lint-flake8-mode)
+endif# NO-LINT-FLAKE8
+
+## -----------------------------------------------------------------------
+## Intent: exhaustive flake8 syntax checking
+## -----------------------------------------------------------------------
+lint-flake8-all: $(venv-activate-script)
+	$(HIDE)$(MAKE) --no-print-directory lint-flake8-install
+
+	$(activate)\
+ && find . \( -name '$(venv-name)' \) -prune -o -name '*.py' -print0 \
+	| $(xargs-n1) flake8 --max-line-length=99 --count
+
+## -----------------------------------------------------------------------
+## Intent: check deps for format and python3 cleanliness
+## Note:
+##   pylint --py3k option no longer supported
+## -----------------------------------------------------------------------
+lint-flake8-modified: $(venv-activate-script)
+	$(HIDE)$(MAKE) --no-print-directory lint-flake8-install
+
+	$(activate)\
+ && flake8 --max-line-length=99 --count $(PYTHON_FILES)
+
+## -----------------------------------------------------------------------
+## Intent:
+## -----------------------------------------------------------------------
+.PHONY: lint-flake8-install
+lint-flake8-install: $(venv-activate-script)
+	@echo
+	@echo "** -----------------------------------------------------------------------"
+	@echo "** python flake8 syntax checking"
+	@echo "** -----------------------------------------------------------------------"
+	$(activate) && pip install --upgrade flake8
+	$(activate) && flake8 --version
+	@echo
+
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
+help::
+	@echo '  lint-flake8          Syntax check python using the flake8 command'
+  ifdef VERBOSE
+	@echo '  $(MAKE) lint-pylint PYTHON_FILES=...'
+	@echo '  lint-flake8-modified  flake8 checking: only modified'
+	@echo '  lint-flake8-all       flake8 checking: exhaustive'
+  endif
+
+$(if $(DEBUG),$(warning LEAVE))
+
+# [EOF]
diff --git a/makefiles/lint/python.mk b/makefiles/lint/python/include.mk
similarity index 62%
rename from makefiles/lint/python.mk
rename to makefiles/lint/python/include.mk
index d8bdfe0..69811a5 100644
--- a/makefiles/lint/python.mk
+++ b/makefiles/lint/python/include.mk
@@ -1,6 +1,6 @@
 # -*- makefile -*-
 # -----------------------------------------------------------------------
-# Copyright 2017-2023 Open Networking Foundation
+# Copyright 2017-2023 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.
@@ -15,20 +15,13 @@
 # limitations under the License.
 # -----------------------------------------------------------------------
 
-PYTHON_FILES ?= $(error PYTHON_FILES= is required)
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+$(if $(UNSTABLE),$(eval lint-python-all := true))
 
-.PHONY: lint-python
-
-lint : lint-python
-
-# check deps for format and python3 cleanliness
-lint-python: vst_venv
-	source ./$</bin/activate \
-	    ; set -u \
-	    ; pylint --py3k $(PYTHON_FILES) \
-	    ; flake8 --max-line-length=99 --count $(PYTHON_FILES)
-
-help::
-	@echo "  lint-python          Syntax check using pylint and flake8"
+include $(MAKEDIR)/lint/python/flake8.mk
+include $(MAKEDIR)/lint/python/pylint.mk
+# include $(MAKEDIR)/lint/python/tox.mk
 
 # [EOF]
diff --git a/makefiles/lint/python/pylint.mk b/makefiles/lint/python/pylint.mk
new file mode 100644
index 0000000..9dc1c7c
--- /dev/null
+++ b/makefiles/lint/python/pylint.mk
@@ -0,0 +1,89 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 2017-2023 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.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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.
+# -----------------------------------------------------------------------
+
+$(if $(DEBUG),$(warning ENTER))
+
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-pylint lint-pylint-all lint-pylint-modified
+
+PYTHON_FILES      ?= $(error PYTHON_FILES= required)
+
+## -----------------------------------------------------------------------
+## Intent: Use the pylint command to perform syntax checking.
+##   o If UNSTABLE=1 syntax check all sources
+##   o else only check sources modified by the developer.
+## Usage:
+##   % make lint UNSTABLE=1
+##   % make lint-pylint-all
+## -----------------------------------------------------------------------
+ifndef NO-LINT-PYLINT
+  lint-pylint-mode := $(if $(have-python-files),modified,all)
+  lint : lint-pylint-$(lint-pylint-mode)
+endif# NO-LINT-PYLINT
+
+## -----------------------------------------------------------------------
+## Intent: exhaustive pylint syntax checking
+## -----------------------------------------------------------------------
+pylint-find-args := $(null)
+pylint-find-args += -name '$(venv-name)'
+pylint-find-args += -o -name 'patches'
+lint-pylint-all: $(venv-activate-script)
+	$(MAKE) --no-print-directory lint-pylint-install
+
+	$(activate)\
+ && find . \( $(pylint-find-args) \) -prune -o -name '*.py' -print0 \
+	| $(xargs-n1) pylint
+
+## -----------------------------------------------------------------------
+## Intent: check deps for format and python3 cleanliness
+## Note:
+##   pylint --py3k option no longer supported
+## -----------------------------------------------------------------------
+lint-pylint-modified: $(venv-activate-script)
+	$(MAKE) --no-print-directory lint-pylint-install
+
+	$(activate) && pylint $(PYTHON_FILES)
+
+## -----------------------------------------------------------------------
+## Intent:
+## -----------------------------------------------------------------------
+.PHONY: lint-pylint-install
+lint-pylint-install: $(venv-activate-script)
+	@echo
+	@echo "** -----------------------------------------------------------------------"
+	@echo "** python pylint syntax checking"
+	@echo "** -----------------------------------------------------------------------"
+	$(activate) && pip install --upgrade pylint
+	$(activate) && pylint --version
+	@echo
+
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
+help::
+	@echo '  lint-pylint          Syntax check python using the pylint command'
+  ifdef VERBOSE
+	@echo '  $(MAKE) lint-pylint PYTHON_FILES=...'
+	@echo '  lint-pylint-modified  pylint checking: only modified'
+	@echo '  lint-pylint-all       pylint checking: exhaustive'
+  endif
+
+$(if $(DEBUG),$(warning LEAVE))
+
+# [EOF]
diff --git a/makefiles/lint/robot.mk b/makefiles/lint/robot.mk
index 1c7119f..fa8175c 100644
--- a/makefiles/lint/robot.mk
+++ b/makefiles/lint/robot.mk
@@ -1,8 +1,8 @@
 # -*- makefile -*-
 # -----------------------------------------------------------------------
-# Copyright 2017-2023 Open Networking Foundation
+# Copyright 2017-2023 Open Networking Foundation (ONF) and the ONF Contributors
 #
-# Licensed under the Apache License, Version 2.0 (the "License");
+# Licensed under the Apache License, Version 2.0 (the "License")
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
@@ -15,7 +15,15 @@
 # limitations under the License.
 # -----------------------------------------------------------------------
 
-ROBOT_FILES ?= $(error ROBOT_FILES= is required)
+$(if $(DEBUG),$(warning ENTER))
+
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-robot lint-robot-all lint-robot-modified
+
+have-robot-files := $(if $(ROBOT_FILES),true)
+ROBOT_FILES      ?= $(error ROBOT_FILES= required)
 
 LINT_ARGS ?= --verbose --configure LineTooLong:130 -e LineTooLong \
              --configure TooManyTestSteps:65 -e TooManyTestSteps \
@@ -25,17 +33,62 @@
              --configure FileTooLong:2000 -e FileTooLong \
              -e TrailingWhitespace
 
+## -----------------------------------------------------------------------
+## Intent: Use the robot command to perform syntax checking.
+##   % make lint
+##   % make lint-robot-all
+##   % make lint-robot-modified
+## -----------------------------------------------------------------------
+ifndef NO-LINT-ROBOT
+  lint-robot-mode := $(if $(have-robot-files),modified,all)
+  lint : lint-robot-$(lint-robot-mode)
+endif# NO-LINT-ROBOT
 
-.PHONY: lint-robot
+## -----------------------------------------------------------------------
+## Intent: exhaustive robot syntax checking
+## -----------------------------------------------------------------------
+lint-robot-all:
+	$(HIDE)$(MAKE) --no-print-directory rflint-install
 
-lint : lint-robot
+	$(activate)\
+ && find . \( -iname '*.robot' \) -print0 \
+	| $(xargs-n1) rflint $(LINT_ARGS)
 
-lint-robot: vst_venv
-	source ./$</bin/activate \
-	    ; set -u \
-	    ; rflint $(LINT_ARGS) $(ROBOT_FILES)
+## -----------------------------------------------------------------------
+## Intent: check deps for format and python3 cleanliness
+## Note:
+##   robot --py3k option no longer supported
+## -----------------------------------------------------------------------
+lint-robot-modified: $(venv-activate-script)
+	$(HIDE)$(MAKE) --no-print-directory rflint-install
 
+	$(activate) && rflint $(LINT_ARGS) $(ROBOT_FILES)
+
+## -----------------------------------------------------------------------
+## Intent: Install the rflint command for syntax checking.
+##   Note: requirements.txt pip install not used here ATM due to implicit
+##         per-repository dependency config to enable checking.
+## -----------------------------------------------------------------------
+rflint-install: $(venv-activate-script)
+	@echo
+	@echo "** -----------------------------------------------------------------------"
+	@echo "** robot syntax checking"
+	@echo "** -----------------------------------------------------------------------"
+	$(activate)\
+ && pip install --upgrade robotframework-lint
+	$(activate) && rflint --version
+	@echo
+
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
 help::
-	@echo "  lint-robot           Syntax check robot sources using rflint"
+	@echo '  lint-robot          Syntax check python using the robot command'
+  ifdef VERBOSE
+	@echo '  lint-robot-all       robot checking: exhaustive'
+	@echo '  lint-robot-modified  robot checking: only modified'
+  endif
+
+$(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]
diff --git a/makefiles/lint/shell.mk b/makefiles/lint/shell.mk
index 9923b72..3c04539 100644
--- a/makefiles/lint/shell.mk
+++ b/makefiles/lint/shell.mk
@@ -1,8 +1,8 @@
 # -*- makefile -*-
 # -----------------------------------------------------------------------
-# Copyright 2017-2023 Open Networking Foundation
+# Copyright 2017-2023 Open Networking Foundation (ONF) and the ONF Contributors
 #
-# Licensed under the Apache License, Version 2.0 (the "License");
+# Licensed under the Apache License, Version 2.0 (the "License")
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
@@ -15,19 +15,73 @@
 # limitations under the License.
 # -----------------------------------------------------------------------
 
-JSON_FILES ?= $(error JSON_FILES= is required)
+$(if $(DEBUG),$(warning ENTER))
 
-.PHONY: lint-shell
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-shell lint-shell-all lint-shell-modified
 
-lint : lint-shell
+have-shell-sources := $(if $(strip $(SHELL_SOURCES)),true)
+SHELL_SOURCES      ?= $(error SHELL_SOURCES= required)
 
-lint-shell:
+## -----------------------------------------------------------------------
+## Intent: Use the shell command to perform syntax checking.
+##   % make lint
+##   % make lint-shell-all
+## -----------------------------------------------------------------------
+ifndef NO-LINT-SHELL
+  lint-shell-mode := $(if $(have-shell-sources),modified,all)
+  lint : lint-shell-$(lint-shell-mode)
+endif# NO-LINT-SHELL
+
+## -----------------------------------------------------------------------
+## Intent: exhaustive shell syntax checking
+## -----------------------------------------------------------------------
+shellcheck-find-args := $(null)
+shellcheck-find-args += -name '$(venv-name)'
+shellcheck-find-args += -o -name 'staging'
+lint-shell-all:
+	$(MAKE) --no-print-directory lint-shellcheck-install
+
+	find . \( $(shellcheck-find-args) \) -prune -name '*.sh' -print0 \
+	    | $(xargs-n1-clean) shellcheck
+
+## -----------------------------------------------------------------------
+## Intent: check deps for format and python3 cleanliness
+## Note:
+##   shell --py3k option no longer supported
+## -----------------------------------------------------------------------
+lint-shell-modified:
+	$(MAKE) --no-print-directory lint-shell-install
+
+	shellcheck $(SHELL_SOURCES)
+
+## -----------------------------------------------------------------------
+## Intent:
+## -----------------------------------------------------------------------
+.PHONY: lint-shellcheck-install
+lint-shellcheck-install:
+	@echo
+	@echo "** -----------------------------------------------------------------------"
+	@echo '** command shell syntax checking'
+	@echo "** -----------------------------------------------------------------------"
+
+        # {apt-get,rpm,yum} install shellcheck
 	shellcheck --version
-	find . \( -name 'staging' -o -name 'vst_venv' \) -prune \
-	    -o -name '*.sh' ! -name 'activate.sh' -print0 \
-	| xargs -0 -n1 shellcheck
+	@echo
 
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
 help::
-	@echo "  lint-shell           Syntax check bash,bourne,etc sources"
+	@echo '  lint-shell          Syntax check sources using shellcheck'
+  ifdef VERBOSE
+	@echo '  $(MAKE) lint-shell SHELL_SOURCES=...'
+	@echo '  lint-shell-modified  shell checking: only modified'
+	@echo '  lint-shell-all       shell checking: exhaustive'
+  endif
+
+$(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]
diff --git a/makefiles/lint/yaml.mk b/makefiles/lint/yaml.mk
index c875686..566ac18 100644
--- a/makefiles/lint/yaml.mk
+++ b/makefiles/lint/yaml.mk
@@ -1,8 +1,8 @@
 # -*- makefile -*-
 # -----------------------------------------------------------------------
-# Copyright 2017-2023 Open Networking Foundation
+# Copyright 2017-2023 Open Networking Foundation (ONF) and the ONF Contributors
 #
-# Licensed under the Apache License, Version 2.0 (the "License");
+# Licensed under the Apache License, Version 2.0 (the "License")
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
@@ -15,18 +15,68 @@
 # limitations under the License.
 # -----------------------------------------------------------------------
 
-YAML_FILES ?= $(error YAML_FILES= is required)
+$(if $(DEBUG),$(warning ENTER))
 
-.PHONY: lint-yaml
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-yaml lint-yaml-all lint-yaml-modified
 
-lint : lint-yaml
+have-yaml-files := $(if $(strip $(YAML_FILES)),true)
+YAML_FILES      ?= $(error YAML_FILES= is required)
 
-lint-yaml: vst_venv
-	source ./$</bin/activate \
-	    ; set -u \
-	    ; yamllint -s $(YAML_FILES)
+## -----------------------------------------------------------------------
+## Intent: Use the yaml command to perform syntax checking.
+##   o If UNSTABLE=1 syntax check all sources
+##   o else only check sources modified by the developer.
+## Usage:
+##   % make lint UNSTABLE=1
+##   % make lint-yaml-all
+## -----------------------------------------------------------------------
+ifndef NO-LINT-YAML
+  lint-yaml-mode := $(if $(have-yaml-files),modified,all)
+  lint : lint-yaml-$(lint-yaml-mode)
+endif# NO-LINT-YAML
 
+## -----------------------------------------------------------------------
+## Intent: exhaustive yaml syntax checking
+## -----------------------------------------------------------------------
+lint-yaml-all:
+	$(HIDE)$(MAKE) --no-print-directory lint-yaml-install
+
+	find . \( -iname '*.yaml' -o -iname '*.yml' \) -print0 \
+	    | $(xargs-n1-clean) yamllint --strict
+
+## -----------------------------------------------------------------------
+## Intent: check deps for format and python3 cleanliness
+## Note:
+##   yaml --py3k option no longer supported
+## -----------------------------------------------------------------------
+lint-yaml-modified:
+	$(HIDE)$(MAKE) --no-print-directory lint-yaml-install
+	yamllint -s $(YAML_FILES)
+
+## -----------------------------------------------------------------------
+## Intent:
+## -----------------------------------------------------------------------
+lint-yaml-install:
+	@echo
+	@echo "** -----------------------------------------------------------------------"
+	@echo "** yaml syntax checking"
+	@echo "** -----------------------------------------------------------------------"
+	yamllint --version
+	@echo
+
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
 help::
-	@echo "  lint-yaml            Syntax check yaml source using yamllint"
+	@echo '  lint-yaml          Syntax check python using the yaml command'
+  ifdef VERBOSE
+	@echo '  lint-yaml-all       yaml checking: exhaustive'
+	@echo '  lint-yaml-modified  yaml checking: only modified'
+  endif
+
+$(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]
diff --git a/makefiles/patches/include.mk b/makefiles/patches/include.mk
index 2bd1bfd..4accdf2 100644
--- a/makefiles/patches/include.mk
+++ b/makefiles/patches/include.mk
@@ -27,7 +27,9 @@
 patch-gather-args += '-e' 'from collections import Mapping'
 patch-gather-args += '-e' 'from collections import MutableMapping'
 
-VENV_NAME   ?= $(error $(MAKE) VENV_NAME= is required)
+# Defined by [Mm]akefile or makefiles/virtualenv.mk
+venv-name   ?= $(error $(MAKE) venv-name= is required)
+
 PATCH_PATH  ?= $(error $(MAKE) PATCH_PATH= is required)
 
 ## -----------------------------------------------------------------------
@@ -38,7 +40,7 @@
 ## -----------------------------------------------------------------------
 ## -----------------------------------------------------------------------
 patch-diff:
-	$(HIDE)diff -qr staging $(VENV_NAME) \
+	$(HIDE)diff -qr staging $(venv-name) \
 	    | awk '{print "# diff -Naur "$$2" "$$4}' \
 	    | tee $@.log
 
@@ -46,16 +48,16 @@
 ## -----------------------------------------------------------------------
 patch-create:
 	mkdir -p patches/$(PATCH_PATH)
-	diff -Naur staging/$(PATCH_PATH) $(VENV_NAME)/$(PATCH_PATH) | tee patches/$(PATCH_PATH)/patch
+	diff -Naur staging/$(PATCH_PATH) $(venv-name)/$(PATCH_PATH) | tee patches/$(PATCH_PATH)/patch
 	exit 1
 
 ## -----------------------------------------------------------------------
 ## -----------------------------------------------------------------------
 patch-init:
-	find "$(VENV_NAME)" -name '__pycache__' -type d -print0 \
+	find "$(venv-name)" -name '__pycache__' -type d -print0 \
 	    | xargs -I'{}' --null --no-run-if-empty $(RM) -r {}
 	mkdir -p staging
-	rsync -rv --checksum "$(VENV_NAME)/." "staging/."
+	rsync -rv --checksum "$(venv-name)/." "staging/."
 	@echo "Modify files beneath staging/ to create a patch source"
 
 # [SEE ALSO]
diff --git a/makefiles/todo.mk b/makefiles/todo.mk
new file mode 100644
index 0000000..b122a9e
--- /dev/null
+++ b/makefiles/todo.mk
@@ -0,0 +1,35 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# 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.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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
+# -----------------------------------------------------------------------
+
+$(if $(DEBUG),$(warning ENTER))
+
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
+todo ::
+	@echo '[TODO]'
+
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
+help ::
+	@echo '  todo                Display future enhancement list.'
+
+$(if $(DEBUG),$(warning LEAVE))
+
+# [EOF]
diff --git a/makefiles/virtualenv.mk b/makefiles/virtualenv.mk
index d54bfda..bcda734 100644
--- a/makefiles/virtualenv.mk
+++ b/makefiles/virtualenv.mk
@@ -1,6 +1,6 @@
 # -*- makefile -*-
 ## -----------------------------------------------------------------------
-# Copyright 2017-2023 Open Networking Foundation
+# Copyright 2017-2023 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.
@@ -15,18 +15,73 @@
 # limitations under the License.
 ## -----------------------------------------------------------------------
 
-# virtualenv for the robot tools
-# VOL-2724 Invoke pip via python3 to avoid pathname too long on QA jobs
+$(if $(DEBUG),$(warning ENTER))
 
-vst_venv-2 : vst_venv/bin/activate requirements.txt
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: venv
 
-vst_venv/bin/activate: requirements.txt
-	virtualenv -p python3 $@
+##------------------##
+##---]  LOCALS  [---##
+##------------------##
+venv-name            ?= .venv#                            # default install directory
+venv-abs-path        := $(PWD)/$(venv-name)
 
-	@echo	
-	@[ -r requirements.txt ]\
-  && { echo "python -m pip install -r requirements.txt"; }\
-  && source ./$@/bin/activate\
-  && python -m pip install -r requirements.txt
+venv-activate-script := $(venv-name)/bin/activate#        # dependency
+
+# Intent: activate= is a macro for accessing the virtualenv activation script#
+#  Usage: $(activate) && python
+activate             ?= set +u && source $(venv-activate-script) && set -u
+
+## -----------------------------------------------------------------------
+## Intent: Activate script path dependency
+## Usage:
+##    o place on the right side of colon as a target dependency
+##    o When the script does not exist install the virtual env and display.
+## -----------------------------------------------------------------------
+$(venv-activate-script):
+	@echo
+	@echo "============================="
+	@echo "Installing python virtual env"
+	@echo "============================="
+	virtualenv -p python3 $(venv-name)
+	$(activate) && python -m pip install --upgrade pip
+	$(activate) && pip install --upgrade setuptools
+	$(activate) && { [[ -r requirements.txt ]] && python -m pip install -r requirements.txt; }
+	$(activate) && python --version
+
+ifndef NO_PYTHON_UPGRADE_PATCHING
+	@echo
+	@echo '** -----------------------------------------------------------------------'
+	@echo '** Applying python virtualenv patches as needed (v3.10+)'
+	@echo '** -----------------------------------------------------------------------'
+	./patches/python_310_migration.sh '--venv' '$(venv-name)' 'apply'
+endif
+
+## -----------------------------------------------------------------------
+## Intent: Explicit named installer target w/o dependencies.
+##         Makefile targets should depend on venv-activate-script.
+## -----------------------------------------------------------------------
+venv: $(venv-activate-script)
+
+## -----------------------------------------------------------------------
+## Intent: Revert installation to a clean checkout
+## -----------------------------------------------------------------------
+sterile :: clean
+	$(RM) -r "$(venv-abs-path)"
+
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
+help ::
+	@echo
+	@echo '[VIRTUAL ENV]'
+	@echo '  venv                Create a python virtual environment'
+	@echo '    venv-name=        Subdir name for virtualenv install'
+	@echo '  venv-activate-script         make macro name'
+	@echo '      $$(target) dependency    install python virtualenv'
+	@echo '      source $$(macro) && cmd  configure env and run cmd'
+
+$(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]