From f0826eaaf74167da2d7e4e95c50268ad6b74b515 Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Thu, 1 Jan 2026 12:22:08 -0800
Subject: [PATCH 01/14] Implement and use pkghash.make_version().

---
 LabGym/gui_main.py         |  5 +++--
 LabGym/myargparse.py       |  5 +++--
 LabGym/pkghash/__init__.py | 18 ++++++++++++++++++
 LabGym/pkghash/hash.py     |  2 ++
 LabGym/pkghash/lookup.py   | 15 +++++++++++++++
 LabGym/probes.py           |  8 +++++---
 LabGym/registration.py     |  4 ++--
 7 files changed, 48 insertions(+), 9 deletions(-)
 create mode 100644 LabGym/pkghash/__init__.py
 create mode 100644 LabGym/pkghash/hash.py
 create mode 100644 LabGym/pkghash/lookup.py

diff --git a/LabGym/gui_main.py b/LabGym/gui_main.py
index 8f32a4fc..3316818e 100644
--- a/LabGym/gui_main.py
+++ b/LabGym/gui_main.py
@@ -34,7 +34,7 @@
 import wx.lib.agw.hyperlink as hl
 
 # Local application/library specific imports.
-from LabGym import __version__
+from LabGym import __version__, pkghash
 from .gui_utils import add_or_select_notebook_page
 logger.debug('importing %s ...', '.gui_categorizer')
 from .gui_categorizer import PanelLv2_GenerateExamples,PanelLv2_TrainCategorizers,PanelLv2_SortBehaviors,PanelLv2_TestCategorizers
@@ -367,7 +367,8 @@ class MainFrame(wx.Frame):
 	"""Main frame and its notebook."""
 
 	def __init__(self):
-		super().__init__(None, title=f'LabGym v{__version__}')
+		version_with_hash = pkghash.make_version(__version__)
+		super().__init__(None, title=f'LabGym v{version_with_hash}')
 
 		self.SetSize((1000, 600))
 
diff --git a/LabGym/myargparse.py b/LabGym/myargparse.py
index 6b52f0a4..abe82df5 100644
--- a/LabGym/myargparse.py
+++ b/LabGym/myargparse.py
@@ -27,7 +27,7 @@
 # (none)
 
 # Local application/library specific imports.
-from LabGym import __version__ as version
+from LabGym import __version__, pkghash
 
 
 # result is a dict with keys that are string, and vals that are
@@ -176,7 +176,8 @@ def parse_args() -> ResultType:
 
 		elif arg in ['--version']:
 			# Print version msg to stdout and exit 0.
-			print(f'version: {version}')
+			version_with_hash = pkghash.make_version(__version__)
+			print(f'version: {version_with_hash}')
 			sys.exit()
 
 		elif arg == '--':
diff --git a/LabGym/pkghash/__init__.py b/LabGym/pkghash/__init__.py
new file mode 100644
index 00000000..27ab070e
--- /dev/null
+++ b/LabGym/pkghash/__init__.py
@@ -0,0 +1,18 @@
+"""
+This package supports an enhanced "version" reporting.
+
+The LabGym package defines its __version__ in LabGym/__init__.py.
+It's available to LabGym modules as
+	from . import __version__
+	# or, from LabGym import __version__
+
+To support enhanced version reporting that includes hash info for
+integrity checking,
+	from . import __version__, pkghash
+	# or, from LabGym import __version__, pkghash
+
+	version_with_hash = pkghash.make_version(__version__)
+"""
+
+from .hash import get_hash
+from .lookup import lookup, make_version
diff --git a/LabGym/pkghash/hash.py b/LabGym/pkghash/hash.py
new file mode 100644
index 00000000..ab36f397
--- /dev/null
+++ b/LabGym/pkghash/hash.py
@@ -0,0 +1,2 @@
+def get_hash():
+	return '2718281828459045'
diff --git a/LabGym/pkghash/lookup.py b/LabGym/pkghash/lookup.py
new file mode 100644
index 00000000..35295e55
--- /dev/null
+++ b/LabGym/pkghash/lookup.py
@@ -0,0 +1,15 @@
+"""
+The term "hash" is commonly used both as verb and as noun.
+Here, to avoid confusion,
+	hash is the name of the package module implementing the function
+	get_hash is the function (the verb)
+	hash_value is the return value (the noun)
+"""
+from . import get_hash
+
+def lookup():
+	pass
+
+def make_version(version):
+	hash_value = get_hash()
+	return f'{version}+{hash_value[:4]}'
diff --git a/LabGym/probes.py b/LabGym/probes.py
index 7e6d643a..e040f3c0 100644
--- a/LabGym/probes.py
+++ b/LabGym/probes.py
@@ -29,7 +29,7 @@
 import packaging  # Core utilities for Python packages
 
 # Local application/library specific imports.
-from LabGym import __version__ as version
+from LabGym import __version__, pkghash
 from LabGym import central_logging, registration
 from LabGym import config
 from LabGym import userdata_survey
@@ -113,7 +113,7 @@ def probes() -> None:
 		# then expire or void the "skip-henceforth" behavior.
 		skip_pass_void = (reginfo is not None
 			and reginfo.get('name') == 'skip'
-			and packaging.version.parse(version)
+			and packaging.version.parse(__version__)
 				!= packaging.version.parse(reginfo.get('version'))
 			)
 
@@ -171,6 +171,8 @@ def get_context(anonymous: bool=False) -> dict:
 	except Exception:
 		reginfo_uuid = None
 
+	version_with_hash = pkghash.make_version(__version__)
+
 	result = {
 		'schema': 'context 2025-08-10',
 
@@ -180,7 +182,7 @@ def get_context(anonymous: bool=False) -> dict:
 		'python_version': platform.python_version(),
 
 		# LabGym sw
-		'version': version,  # LabGym version
+		'version': version_with_hash,  # LabGym version
 
 		# User info
 		# 'username': getpass.getuser(),
diff --git a/LabGym/registration.py b/LabGym/registration.py
index 4009c6db..e8eb5087 100644
--- a/LabGym/registration.py
+++ b/LabGym/registration.py
@@ -83,7 +83,7 @@
 import yaml  # PyYAML, YAML parser and emitter for Python
 
 # Local application/library specific imports.
-from LabGym import __version__ as version
+from LabGym import __version__
 from LabGym import central_logging
 from LabGym import config
 from LabGym import mywx
@@ -338,7 +338,7 @@ def register(central_logger=None) -> None:
 
 		'platform': platform.platform(),
 		'node': platform.node(),
-		'version': version,  # LabGym version
+		'version': __version__,  # LabGym version
 		})
 
 	try:

From e221efec65208272e9479dac23c27dc692eb21cb Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Sat, 3 Jan 2026 11:47:47 -0800
Subject: [PATCH 02/14] Implement the hashing.

---
 LabGym/gui_main.py           |   2 +-
 LabGym/myargparse.py         |   2 +-
 LabGym/pkghash/__init__.py   |  31 +++++----
 LabGym/pkghash/hash.py       | 128 ++++++++++++++++++++++++++++++++++-
 LabGym/pkghash/lookup.py     | 118 +++++++++++++++++++++++++++++---
 LabGym/pkghash/versions.toml |   5 ++
 LabGym/probes.py             |   3 +-
 7 files changed, 260 insertions(+), 29 deletions(-)
 create mode 100644 LabGym/pkghash/versions.toml

diff --git a/LabGym/gui_main.py b/LabGym/gui_main.py
index 3316818e..0054a42a 100644
--- a/LabGym/gui_main.py
+++ b/LabGym/gui_main.py
@@ -367,7 +367,7 @@ class MainFrame(wx.Frame):
 	"""Main frame and its notebook."""
 
 	def __init__(self):
-		version_with_hash = pkghash.make_version(__version__)
+		version_with_hash = pkghash.labgym_version_with_hash()
 		super().__init__(None, title=f'LabGym v{version_with_hash}')
 
 		self.SetSize((1000, 600))
diff --git a/LabGym/myargparse.py b/LabGym/myargparse.py
index abe82df5..6a80088d 100644
--- a/LabGym/myargparse.py
+++ b/LabGym/myargparse.py
@@ -176,7 +176,7 @@ def parse_args() -> ResultType:
 
 		elif arg in ['--version']:
 			# Print version msg to stdout and exit 0.
-			version_with_hash = pkghash.make_version(__version__)
+			version_with_hash = pkghash.labgym_version_with_hash()
 			print(f'version: {version_with_hash}')
 			sys.exit()
 
diff --git a/LabGym/pkghash/__init__.py b/LabGym/pkghash/__init__.py
index 27ab070e..e8914c99 100644
--- a/LabGym/pkghash/__init__.py
+++ b/LabGym/pkghash/__init__.py
@@ -1,18 +1,23 @@
-"""
-This package supports an enhanced "version" reporting.
+"""Support hash-included version reporting for LabGym.
+
+Provide functions to support hash-included version reporting for the
+LabGym package.
+
+The LabGym package defines __version__ in LabGym/__init__.py.
 
-The LabGym package defines its __version__ in LabGym/__init__.py.
-It's available to LabGym modules as
-	from . import __version__
-	# or, from LabGym import __version__
+Example
+	from LabGym import __version__, pkghash
+	# __version__ is like '2.9.6'
 
-To support enhanced version reporting that includes hash info for
-integrity checking,
-	from . import __version__, pkghash
-	# or, from LabGym import __version__, pkghash
+	version_with_hash = pkghash.labgym_version_with_hash()
+	# version_with_hash is like '2.9.6 (7b2c)'
 
-	version_with_hash = pkghash.make_version(__version__)
+Development Notes
+	These formats were considered:
+		2.9.6.7b2c
+		2.9.6+7b2c
+		2.9.6 (7b2c)
+		2.9.6 (hash: 7b2c)
 """
 
-from .hash import get_hash
-from .lookup import lookup, make_version
+from .lookup import labgym_version_with_hash
diff --git a/LabGym/pkghash/hash.py b/LabGym/pkghash/hash.py
index ab36f397..55ef7488 100644
--- a/LabGym/pkghash/hash.py
+++ b/LabGym/pkghash/hash.py
@@ -1,2 +1,126 @@
-def get_hash():
-	return '2718281828459045'
+"""Support hash-included version reporting for LabGym.
+
+Provide functions to support hash-included version reporting for the
+LabGym package.
+
+Public Functions
+	get_hashval -- Return a hashval (a signature) of the contents of the folder.
+"""
+
+# Allow use of newer syntax Python 3.10 type hints in Python 3.9.
+from __future__ import annotations
+
+# Standard library imports.
+import hashlib
+import logging
+import os
+from pathlib import Path
+
+# Related third party imports.
+# None
+
+# Local application/library specific imports.
+# None
+
+
+logger = logging.getLogger(__name__)
+
+_cached_hashvals = {}
+
+
+def get_hashval(folder: str) -> str:
+	"""Return a hashval (a signature) of the contents of the folder.
+
+	On first call to this function with this folder, compute the hash
+	value string, and cache it in a module-level dictionary variable.
+	On subsequent calls to this function with the same folder, return
+	the cached hash value string.
+	"""
+
+	folder_pathobj = Path(folder).resolve()
+
+	hashval = _cached_hashvals.get(folder_pathobj)
+
+	if hashval is not None:
+		return hashval
+
+	hashval = _walk_and_hash(folder_pathobj)
+	_cached_hashvals.update({folder_pathobj: hashval})
+
+	return hashval
+
+
+def _walk_and_hash(folder: Path) -> str:
+	"""Walk a folder and return the accumulated the MD5 hash for files.
+
+	*   Skip dirs that don't have __init__.py.
+		All files of interest are in package dirs, right?
+
+		Actually, no.  Generally, a package dir might have source-code
+		in package subdirs that are not actually traditional packages
+		themselves. (Implicit Namespace Packages)
+
+		A different approach would be to create an empty file '.nohash'
+		in dirs that should be skipped, and test for its existence
+		during the walk.
+
+	*   Skip top-level dirs detectron2, detectors, models.
+
+	*   Skip non-py-files.
+	"""
+
+	hasher = hashlib.md5()
+	os.chdir(folder)
+
+	for root, dirs, files in os.walk('.'):
+		# walk "sorted"
+		dirs.sort()
+		files.sort()
+
+		# Skip dirs that don't have __init__.py.
+		if '__init__.py' not in files:
+			# this is not a "traditional" package dir...
+			# skip further descent
+			dirs.clear()
+			# skip processing files in this dir
+			continue
+
+		# Skip top-level dirs detectron2, detectors, models.
+		if root == '.':
+			for name in ['detectron2', 'detectors', 'models']:
+				if name in dirs:
+					dirs.remove(name)
+
+		for file in files:
+			# Skip non-py-files.
+			if not file.endswith('.py'):
+				continue
+
+			file_path = os.path.join(root, file)
+			_add_file_to_hash(hasher, file_path)
+
+	hashval = hasher.hexdigest()
+	logger.debug('%s: %r', 'hashval', hashval)
+	return hashval
+
+
+def _add_file_to_hash(hasher, file_path: str) -> None:
+	"""Add the filepath and the file content to the hash.
+
+	Hash is sensitive to
+		filename case -- foo.py is different from Foo.py
+		file rename -- foo.py is different from goo.py
+	"""
+
+	filename = Path(file_path).as_posix()  # forward slash, even on Windows
+	logger.debug('%s: %r', 'filename', filename)
+
+	hasher.update(filename.encode('utf-8'))
+
+	try:
+		with open(file_path, 'rb') as f:
+			# Read file in 8KB chunks to handle large files efficiently
+			while chunk := f.read(8192):
+				hasher.update(chunk)
+	except (OSError, IOError) as e:
+		logger.warning(f'Trouble...{e}')
diff --git a/LabGym/pkghash/lookup.py b/LabGym/pkghash/lookup.py
index 35295e55..1031204f 100644
--- a/LabGym/pkghash/lookup.py
+++ b/LabGym/pkghash/lookup.py
@@ -1,15 +1,111 @@
-"""
+"""Support hash-included version reporting for LabGym.
+
+Provide functions to support hash-included version reporting for the
+LabGym package.
+
+Public Functions
+	labgym_version_with_hash -- Return a hash-included version string
+		for LabGym.
+
 The term "hash" is commonly used both as verb and as noun.
-Here, to avoid confusion,
-	hash is the name of the package module implementing the function
-	get_hash is the function (the verb)
-	hash_value is the return value (the noun)
+To reduce confusion, these terms may be used to improve clarity.
+	get_hashval -- the function (the verb)
+	hashval -- the return string value (the noun) from the function
+
+Examples
+	pkghash.labgym_version_with_hash()
+	returns a str like '2.9.6+be19',
+	or returns '2.9.6' if the version+hashval is in known_versions.
+
+	pkghash.labgym_version_with_hash(maxlen=6)
+	returns a str like '2.9.6+be19e5',
+	or returns '2.9.6' if the version+hashval is in known_versions.
+
+	pkghash.labgym_version_with_hash(maxlen=None,
+		suppress_if_known=False)
+	returns a str like '2.9.6+be19e53c16ff24a33c48b517d870147b'
+	even if version+hashval is in known_versions.
+
+Why?  Isn't LabGym.__version__ sufficiently identifying?
+The purpose of this "enhanced" version-string is to make obvious
+when the user or developer is running customized/modified LabGym.
+
+This helps to
+1.  make developer usage scrubbable from LabGym from overall usage
+	stats.
+2.  avoid developer-investigation effort for behavior of a
+	customized LabGym.
 """
-from . import get_hash
 
-def lookup():
-	pass
+# Allow use of newer syntax Python 3.10 type hints in Python 3.9.
+from __future__ import annotations
+
+# Standard library imports.
+import logging
+from pathlib import Path
+from typing import List
+
+# Related third party imports.
+try:
+	# tomllib is included in the Python Standard Library since version 3.11
+	import tomllib  # type: ignore
+except ModuleNotFoundError:
+	import tomli as tomllib  # A lil' TOML parser
+
+# Local application/library specific imports.
+from .hash import get_hashval
+import LabGym
+
+
+logger = logging.getLogger(__name__)
+
+
+labgym_package_folder = str(Path(LabGym.__file__).parent)
+version = LabGym.__version__
+versions_file = Path(__file__).parent / 'versions.toml'
+
+
+def _get_known_versions() -> List[str]:
+	"""Read list of known version+hash strings from toml-file, and return it."""
+
+	try:
+		with open(versions_file, 'rb') as f:
+			known_versions = tomllib.load(f).get('known_versions')
+		assert isinstance(known_versions, list)
+	except Exception as e:
+		# an unreadable toml-file produces an empty list
+		logger.warning(f'Trouble reading {versions_file}.  {e}')
+		known_versions = []
+
+	logger.debug('%s: %r', 'known_versions', known_versions)
+
+	return known_versions
+
+
+def labgym_version_with_hash(
+		maxlen=4,
+		suppress_if_known=True,
+		) -> str:
+	"""Return a hash-included version string for LabGym.
+
+	If this LabGym package's version_with_hash package matches a
+	reference value stored in versions.toml, then this LabGym is judged
+	genuine/unmodified, so the hashval suffix is suppressed (unless
+	suppress_if_known is True).
+	"""
+
+	hashval: str = get_hashval(labgym_package_folder)
+
+	known_enhanced_versions = _get_known_versions()
+
+	if (f'{version} ({hashval})' in known_enhanced_versions
+			and suppress_if_known == True):
+		result = version  # without hashval
+
+	elif maxlen is not None:
+		result = f'{version} ({hashval[:maxlen]})'
+	else:
+		result = f'{version} ({hashval})'
 
-def make_version(version):
-	hash_value = get_hash()
-	return f'{version}+{hash_value[:4]}'
+	logger.debug('%s: %r', 'result', result)
+	return result
diff --git a/LabGym/pkghash/versions.toml b/LabGym/pkghash/versions.toml
new file mode 100644
index 00000000..fa39341a
--- /dev/null
+++ b/LabGym/pkghash/versions.toml
@@ -0,0 +1,5 @@
+known_versions = [
+    # d41d... is the md5hash of zero bytes, so only matches no-content.
+    '2.9.6 (d41d8cd98f00b204e9800998ecf8427e)',
+    '2.9.6 (dfe2c280cb0038f808f13eb2cde9adb0)',
+]
diff --git a/LabGym/probes.py b/LabGym/probes.py
index e040f3c0..1a32cab6 100644
--- a/LabGym/probes.py
+++ b/LabGym/probes.py
@@ -171,7 +171,8 @@ def get_context(anonymous: bool=False) -> dict:
 	except Exception:
 		reginfo_uuid = None
 
-	version_with_hash = pkghash.make_version(__version__)
+	version_with_hash = pkghash.labgym_version_with_hash(
+		maxlen=None, suppress_if_known=False)
 
 	result = {
 		'schema': 'context 2025-08-10',

From a5ac208928c3f62ee484428fbc93518b49250676 Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Sat, 3 Jan 2026 16:19:30 -0800
Subject: [PATCH 03/14] Set level for LabGym.pkghash.hash

---
 LabGym/logging.yaml | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/LabGym/logging.yaml b/LabGym/logging.yaml
index ba646688..d38b1375 100644
--- a/LabGym/logging.yaml
+++ b/LabGym/logging.yaml
@@ -16,7 +16,11 @@ version: 1
 formatters:
     myformat:
         datefmt: "%Y-%m-%d %H:%M:%S"
-        format: "%(asctime)s\t%(levelname)s\t[%(thread)d:%(name)s:%(module)s:%(lineno)d]\t%(message)s"
+
+        # format: "%(asctime)s\t%(levelname)s\t[%(thread)d:%(name)s:%(module)s:%(lineno)d]\t%(message)s"
+        # format: "%(asctime)s\t%(levelname)s\t[%(name)s:%(module)s:%(lineno)d]\t%(message)s"
+        format: "%(asctime)s\t%(levelname)s\t[%(module)s:%(lineno)d]\t%(message)s"
+
     mycompactformat:
         datefmt: "%H:%M:%S"
         format: "%(asctime)s\t%(levelname)s\t%(message)s"
@@ -40,4 +44,7 @@ loggers:
     urllib3.connectionpool:
         level: INFO
 
+    LabGym.pkghash.hash:
+        level: INFO
+
 disable_existing_loggers: false

From f336012e0b252e7d90bae147b024fa369b719762 Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Tue, 6 Jan 2026 12:55:22 -0800
Subject: [PATCH 04/14] Improved robustness wrt CRLF and indent-style.

---
 LabGym/logging.yaml           |  3 --
 LabGym/pkghash/__init__.py    | 42 +++++++++++++++++++++++++--
 LabGym/pkghash/hash.py        | 54 +++++++++++++++++++++++++++++++----
 LabGym/pkghash/lookup.py      | 25 ++++++++--------
 LabGym/pkghash/versions.toml  |  2 --
 docs/contributing/internal.md | 11 +++++++
 6 files changed, 111 insertions(+), 26 deletions(-)

diff --git a/LabGym/logging.yaml b/LabGym/logging.yaml
index d38b1375..a66edc38 100644
--- a/LabGym/logging.yaml
+++ b/LabGym/logging.yaml
@@ -44,7 +44,4 @@ loggers:
     urllib3.connectionpool:
         level: INFO
 
-    LabGym.pkghash.hash:
-        level: INFO
-
 disable_existing_loggers: false
diff --git a/LabGym/pkghash/__init__.py b/LabGym/pkghash/__init__.py
index e8914c99..d0b8a567 100644
--- a/LabGym/pkghash/__init__.py
+++ b/LabGym/pkghash/__init__.py
@@ -12,12 +12,50 @@
 	version_with_hash = pkghash.labgym_version_with_hash()
 	# version_with_hash is like '2.9.6 (7b2c)'
 
-Development Notes
-	These formats were considered:
+Notes
+*   These formats were considered...
 		2.9.6.7b2c
 		2.9.6+7b2c
 		2.9.6 (7b2c)
 		2.9.6 (hash: 7b2c)
+
+*   One way to silence the LabGym.pkghash.hash debug messages is to set
+	the logger's level to INFO, by modifying ~/.labgym/logging.yaml, in
+	loggers, like
+		LabGym.pkghash.hash:
+			level: INFO
+
+*   As a final step before releasing a new version, the developer should
+	update versions.toml with the reference version+hashval.
+
+	1.  run
+			LabGym --debug --version
+		which reports like
+			...
+			DEBUG:LabGym.pkghash.lookup:version_with_longhash: '2.9.7 (a48c52287fc078897a30f19b05f1c12a)'
+			DEBUG:LabGym.pkghash.lookup:known_versions: ['2.9.6 (d41d8cd98f00b204e9800998ecf8427e)']
+			DEBUG:LabGym.pkghash.lookup:result: '2.9.7 (a48c)'
+			version: 2.9.7 (a48c)
+
+	2.  update versions.toml from old, like
+			known_versions = [
+				'2.9.6 (d41d8cd98f00b204e9800998ecf8427e)',
+			]
+		to new like
+			known_versions = [
+				# '2.9.6 (d41d8cd98f00b204e9800998ecf8427e)',
+				'2.9.7 (a48c52287fc078897a30f19b05f1c12a)',
+			]
+
+	Should we keep old known_values in the list defined in versions.toml?
+	They won't be matched, because LabGym.__version__ is updated, but
+	they have some value, so, yes preserve them as a comment.
+
+	What if this final step (update versions.toml) is inadvertently
+	skipped during a release?
+	Only that the user-visible id will contain the hashval even when
+	LabGym is clean... if there's no reference value to match, then it
+	can't be suppressed.  In other words, a little extra visual noise.
 """
 
 from .lookup import labgym_version_with_hash
diff --git a/LabGym/pkghash/hash.py b/LabGym/pkghash/hash.py
index 55ef7488..77957f4d 100644
--- a/LabGym/pkghash/hash.py
+++ b/LabGym/pkghash/hash.py
@@ -12,9 +12,13 @@
 
 # Standard library imports.
 import hashlib
+import itertools
 import logging
 import os
 from pathlib import Path
+import re
+import sys
+import time
 
 # Related third party imports.
 # None
@@ -73,7 +77,7 @@ def _walk_and_hash(folder: Path) -> str:
 	os.chdir(folder)
 
 	for root, dirs, files in os.walk('.'):
-		# walk "sorted"
+		# walk in "sorted" order
 		dirs.sort()
 		files.sort()
 
@@ -110,17 +114,55 @@ def _add_file_to_hash(hasher, file_path: str) -> None:
 	Hash is sensitive to
 		filename case -- foo.py is different from Foo.py
 		file rename -- foo.py is different from goo.py
+
+	*   replace leading tabs with 4-spaces,
+		replace trailing \r\n with \n
+		Why?  To normalize the content, as developers might run a genuine,
+		but smudge-filtered copy.
 	"""
 
 	filename = Path(file_path).as_posix()  # forward slash, even on Windows
-	logger.debug('%s: %r', 'filename', filename)
 
 	hasher.update(filename.encode('utf-8'))
 
 	try:
-		with open(file_path, 'rb') as f:
-			# Read file in 8KB chunks to handle large files efficiently
-			while chunk := f.read(8192):
-				hasher.update(chunk)
+		# with open(file_path, 'rb') as f:
+		#     # Read file in 8KB chunks to handle large files efficiently
+		#     while chunk := f.read(8192):
+		#         hasher.update(chunk)
+
+		with open(file_path, 'r') as f:
+			# Read file in 200-line chunks to handle large files efficiently
+			for chunk in _myreadlines(f):
+				for i, line in enumerate(chunk):
+					line = _expand(line)  # expand leading tabs to 4 spaces
+					# replace trailing space, incl LF or CRLF, with LF
+					line = line.rstrip() + '\n'
+					chunk[i] = line
+
+				hasher.update(''.join(chunk).encode('utf-8'))
+
 	except (OSError, IOError) as e:
 		logger.warning(f'Trouble...{e}')
+
+	logger.debug('%s: %r', 'filename, hasher.hexdigest()',
+		(filename, hasher.hexdigest()))
+
+
+def _myreadlines(f, n=200):
+	"""Read n lines from f, and yield a list of the n strings."""
+	while True:
+		nline_chunk = list(itertools.islice(f, n))
+		if not nline_chunk:
+			 break
+		yield nline_chunk
+
+
+def _expand(line, n=4):
+	"""Expand leading tabs to n spaces."""
+	match = re.match(r'^(\t+)', line)
+	if match:
+		leading_tabs = match.group(0)
+		spaces = ' ' * len(leading_tabs) * n
+		return spaces + line[len(leading_tabs):]
+	return line
diff --git a/LabGym/pkghash/lookup.py b/LabGym/pkghash/lookup.py
index 1031204f..c4c7b11b 100644
--- a/LabGym/pkghash/lookup.py
+++ b/LabGym/pkghash/lookup.py
@@ -14,16 +14,16 @@
 
 Examples
 	pkghash.labgym_version_with_hash()
-	returns a str like '2.9.6+be19',
+	returns a str like '2.9.6 (be19)',
 	or returns '2.9.6' if the version+hashval is in known_versions.
 
 	pkghash.labgym_version_with_hash(maxlen=6)
-	returns a str like '2.9.6+be19e5',
+	returns a str like '2.9.6 (be19e5)',
 	or returns '2.9.6' if the version+hashval is in known_versions.
 
 	pkghash.labgym_version_with_hash(maxlen=None,
 		suppress_if_known=False)
-	returns a str like '2.9.6+be19e53c16ff24a33c48b517d870147b'
+	returns a str like '2.9.6 (be19e53c16ff24a33c48b517d870147b)'
 	even if version+hashval is in known_versions.
 
 Why?  Isn't LabGym.__version__ sufficiently identifying?
@@ -31,10 +31,9 @@
 when the user or developer is running customized/modified LabGym.
 
 This helps to
-1.  make developer usage scrubbable from LabGym from overall usage
-	stats.
-2.  avoid developer-investigation effort for behavior of a
-	customized LabGym.
+1.  make developer usage scrubbable from overall LabGym usage stats.
+2.  avoid developer-investigation-effort for behavior in a customized
+	LabGym.
 """
 
 # Allow use of newer syntax Python 3.10 type hints in Python 3.9.
@@ -96,16 +95,16 @@ def labgym_version_with_hash(
 
 	hashval: str = get_hashval(labgym_package_folder)
 
-	known_enhanced_versions = _get_known_versions()
-
-	if (f'{version} ({hashval})' in known_enhanced_versions
-			and suppress_if_known == True):
-		result = version  # without hashval
+	version_with_longhash = f'{version} ({hashval})'
+	logger.debug('%s: %r', 'version_with_longhash', version_with_longhash)
 
+	if (suppress_if_known == True
+		and version_with_longhash in _get_known_versions()):
+			result = version  # without hashval
 	elif maxlen is not None:
 		result = f'{version} ({hashval[:maxlen]})'
 	else:
-		result = f'{version} ({hashval})'
+		result = version_with_longhash
 
 	logger.debug('%s: %r', 'result', result)
 	return result
diff --git a/LabGym/pkghash/versions.toml b/LabGym/pkghash/versions.toml
index fa39341a..df83357b 100644
--- a/LabGym/pkghash/versions.toml
+++ b/LabGym/pkghash/versions.toml
@@ -1,5 +1,3 @@
 known_versions = [
-    # d41d... is the md5hash of zero bytes, so only matches no-content.
     '2.9.6 (d41d8cd98f00b204e9800998ecf8427e)',
-    '2.9.6 (dfe2c280cb0038f808f13eb2cde9adb0)',
 ]
diff --git a/docs/contributing/internal.md b/docs/contributing/internal.md
index 2f1407d3..49a010ef 100644
--- a/docs/contributing/internal.md
+++ b/docs/contributing/internal.md
@@ -57,6 +57,17 @@ environment](./setup.md) set up properly. Then, follow these instructions.
 4. Update the changelog in `docs/changelog.md`. After updating the changelog, 
    run `nox -s docs` to ensure that the docs are built properly.
 
+?. Ensure the working dir is "clean", in that there are no uncommitted 
+   py-file changes, because py-file content impacts hash.
+
+   Compute the hash for the LabGym package, and store it in 
+   LabGym/pkghash/versions.toml.  
+   (See instructions in the docstring in LabGym/pkghash/__init__.py.)
+
+   Commit
+   `$ git add LabGym/pkghash/versions.toml`
+   `$ git commit -m "Add reference version+hashval to versions.toml."`  
+
 5. Create a tag for the new version.
 
    Note that the Git tag DOES contain the leading "v". For example, if the new 

From f42e569b23114b7813ec3e47c87e457b5e2cdb9a Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Tue, 6 Jan 2026 13:11:42 -0800
Subject: [PATCH 05/14] Fixed instructions for updating versions.toml.

---
 LabGym/pkghash/__init__.py | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/LabGym/pkghash/__init__.py b/LabGym/pkghash/__init__.py
index d0b8a567..8847dd48 100644
--- a/LabGym/pkghash/__init__.py
+++ b/LabGym/pkghash/__init__.py
@@ -29,13 +29,13 @@
 	update versions.toml with the reference version+hashval.
 
 	1.  run
-			LabGym --debug --version
+			LabGym --debug
 		which reports like
 			...
-			DEBUG:LabGym.pkghash.lookup:version_with_longhash: '2.9.7 (a48c52287fc078897a30f19b05f1c12a)'
-			DEBUG:LabGym.pkghash.lookup:known_versions: ['2.9.6 (d41d8cd98f00b204e9800998ecf8427e)']
-			DEBUG:LabGym.pkghash.lookup:result: '2.9.7 (a48c)'
-			version: 2.9.7 (a48c)
+			DEBUG:lookup:version_with_longhash: '2.9.7 (a48c52287fc078897a30f19b05f1c12a)'
+			DEBUG:lookup:known_versions: ['2.9.6 (d41d8cd98f00b204e9800998ecf8427e)']
+			DEBUG:lookup:result: '2.9.7 (a48c)'
+			...
 
 	2.  update versions.toml from old, like
 			known_versions = [

From 9b82abe43a80490597cea46097f58b34c0b4940c Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Thu, 8 Jan 2026 14:25:51 -0800
Subject: [PATCH 06/14] Revert hash-embellishment on user-facing version string

* revert the extra release-step of updating the lookup table.
* revert using embellished version in main frame title.
---
 LabGym/gui_main.py            |  5 ++---
 docs/contributing/internal.md | 11 -----------
 2 files changed, 2 insertions(+), 14 deletions(-)

diff --git a/LabGym/gui_main.py b/LabGym/gui_main.py
index 0054a42a..8f32a4fc 100644
--- a/LabGym/gui_main.py
+++ b/LabGym/gui_main.py
@@ -34,7 +34,7 @@
 import wx.lib.agw.hyperlink as hl
 
 # Local application/library specific imports.
-from LabGym import __version__, pkghash
+from LabGym import __version__
 from .gui_utils import add_or_select_notebook_page
 logger.debug('importing %s ...', '.gui_categorizer')
 from .gui_categorizer import PanelLv2_GenerateExamples,PanelLv2_TrainCategorizers,PanelLv2_SortBehaviors,PanelLv2_TestCategorizers
@@ -367,8 +367,7 @@ class MainFrame(wx.Frame):
 	"""Main frame and its notebook."""
 
 	def __init__(self):
-		version_with_hash = pkghash.labgym_version_with_hash()
-		super().__init__(None, title=f'LabGym v{version_with_hash}')
+		super().__init__(None, title=f'LabGym v{__version__}')
 
 		self.SetSize((1000, 600))
 
diff --git a/docs/contributing/internal.md b/docs/contributing/internal.md
index 49a010ef..2f1407d3 100644
--- a/docs/contributing/internal.md
+++ b/docs/contributing/internal.md
@@ -57,17 +57,6 @@ environment](./setup.md) set up properly. Then, follow these instructions.
 4. Update the changelog in `docs/changelog.md`. After updating the changelog, 
    run `nox -s docs` to ensure that the docs are built properly.
 
-?. Ensure the working dir is "clean", in that there are no uncommitted 
-   py-file changes, because py-file content impacts hash.
-
-   Compute the hash for the LabGym package, and store it in 
-   LabGym/pkghash/versions.toml.  
-   (See instructions in the docstring in LabGym/pkghash/__init__.py.)
-
-   Commit
-   `$ git add LabGym/pkghash/versions.toml`
-   `$ git commit -m "Add reference version+hashval to versions.toml."`  
-
 5. Create a tag for the new version.
 
    Note that the Git tag DOES contain the leading "v". For example, if the new 

From 64260c7190682e6ed81abcc7eff530e8b7191dc5 Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Thu, 8 Jan 2026 15:34:51 -0800
Subject: [PATCH 07/14] Simplify feature -- no more lookup for reference value.

---
 LabGym/logging.yaml          |  1 -
 LabGym/pkghash/__init__.py   | 36 ++-------------------
 LabGym/pkghash/lookup.py     | 63 ++++--------------------------------
 LabGym/pkghash/versions.toml |  3 --
 LabGym/probes.py             |  3 +-
 5 files changed, 9 insertions(+), 97 deletions(-)
 delete mode 100644 LabGym/pkghash/versions.toml

diff --git a/LabGym/logging.yaml b/LabGym/logging.yaml
index a66edc38..aea270e6 100644
--- a/LabGym/logging.yaml
+++ b/LabGym/logging.yaml
@@ -18,7 +18,6 @@ formatters:
         datefmt: "%Y-%m-%d %H:%M:%S"
 
         # format: "%(asctime)s\t%(levelname)s\t[%(thread)d:%(name)s:%(module)s:%(lineno)d]\t%(message)s"
-        # format: "%(asctime)s\t%(levelname)s\t[%(name)s:%(module)s:%(lineno)d]\t%(message)s"
         format: "%(asctime)s\t%(levelname)s\t[%(module)s:%(lineno)d]\t%(message)s"
 
     mycompactformat:
diff --git a/LabGym/pkghash/__init__.py b/LabGym/pkghash/__init__.py
index 8847dd48..ccb0fd3b 100644
--- a/LabGym/pkghash/__init__.py
+++ b/LabGym/pkghash/__init__.py
@@ -7,10 +7,10 @@
 
 Example
 	from LabGym import __version__, pkghash
-	# __version__ is like '2.9.6'
+	# __version__ is like '2.9.7'
 
 	version_with_hash = pkghash.labgym_version_with_hash()
-	# version_with_hash is like '2.9.6 (7b2c)'
+	# version_with_hash is like '2.9.7 (a48c52287fc078897a30f19b05f1c12a)'
 
 Notes
 *   These formats were considered...
@@ -24,38 +24,6 @@
 	loggers, like
 		LabGym.pkghash.hash:
 			level: INFO
-
-*   As a final step before releasing a new version, the developer should
-	update versions.toml with the reference version+hashval.
-
-	1.  run
-			LabGym --debug
-		which reports like
-			...
-			DEBUG:lookup:version_with_longhash: '2.9.7 (a48c52287fc078897a30f19b05f1c12a)'
-			DEBUG:lookup:known_versions: ['2.9.6 (d41d8cd98f00b204e9800998ecf8427e)']
-			DEBUG:lookup:result: '2.9.7 (a48c)'
-			...
-
-	2.  update versions.toml from old, like
-			known_versions = [
-				'2.9.6 (d41d8cd98f00b204e9800998ecf8427e)',
-			]
-		to new like
-			known_versions = [
-				# '2.9.6 (d41d8cd98f00b204e9800998ecf8427e)',
-				'2.9.7 (a48c52287fc078897a30f19b05f1c12a)',
-			]
-
-	Should we keep old known_values in the list defined in versions.toml?
-	They won't be matched, because LabGym.__version__ is updated, but
-	they have some value, so, yes preserve them as a comment.
-
-	What if this final step (update versions.toml) is inadvertently
-	skipped during a release?
-	Only that the user-visible id will contain the hashval even when
-	LabGym is clean... if there's no reference value to match, then it
-	can't be suppressed.  In other words, a little extra visual noise.
 """
 
 from .lookup import labgym_version_with_hash
diff --git a/LabGym/pkghash/lookup.py b/LabGym/pkghash/lookup.py
index c4c7b11b..fbb80329 100644
--- a/LabGym/pkghash/lookup.py
+++ b/LabGym/pkghash/lookup.py
@@ -4,7 +4,7 @@
 LabGym package.
 
 Public Functions
-	labgym_version_with_hash -- Return a hash-included version string
+	labgym_version_with_hash -- Return a hash-embellished version string
 		for LabGym.
 
 The term "hash" is commonly used both as verb and as noun.
@@ -14,26 +14,11 @@
 
 Examples
 	pkghash.labgym_version_with_hash()
-	returns a str like '2.9.6 (be19)',
-	or returns '2.9.6' if the version+hashval is in known_versions.
-
-	pkghash.labgym_version_with_hash(maxlen=6)
-	returns a str like '2.9.6 (be19e5)',
-	or returns '2.9.6' if the version+hashval is in known_versions.
-
-	pkghash.labgym_version_with_hash(maxlen=None,
-		suppress_if_known=False)
 	returns a str like '2.9.6 (be19e53c16ff24a33c48b517d870147b)'
-	even if version+hashval is in known_versions.
 
 Why?  Isn't LabGym.__version__ sufficiently identifying?
-The purpose of this "enhanced" version-string is to make obvious
-when the user or developer is running customized/modified LabGym.
-
-This helps to
-1.  make developer usage scrubbable from overall LabGym usage stats.
-2.  avoid developer-investigation-effort for behavior in a customized
-	LabGym.
+The purpose of this "enhanced" version-string is to make it possible
+to discern when the user or developer is running customized/modified LabGym.
 """
 
 # Allow use of newer syntax Python 3.10 type hints in Python 3.9.
@@ -61,50 +46,14 @@
 
 labgym_package_folder = str(Path(LabGym.__file__).parent)
 version = LabGym.__version__
-versions_file = Path(__file__).parent / 'versions.toml'
-
-
-def _get_known_versions() -> List[str]:
-	"""Read list of known version+hash strings from toml-file, and return it."""
 
-	try:
-		with open(versions_file, 'rb') as f:
-			known_versions = tomllib.load(f).get('known_versions')
-		assert isinstance(known_versions, list)
-	except Exception as e:
-		# an unreadable toml-file produces an empty list
-		logger.warning(f'Trouble reading {versions_file}.  {e}')
-		known_versions = []
 
-	logger.debug('%s: %r', 'known_versions', known_versions)
-
-	return known_versions
-
-
-def labgym_version_with_hash(
-		maxlen=4,
-		suppress_if_known=True,
-		) -> str:
-	"""Return a hash-included version string for LabGym.
-
-	If this LabGym package's version_with_hash package matches a
-	reference value stored in versions.toml, then this LabGym is judged
-	genuine/unmodified, so the hashval suffix is suppressed (unless
-	suppress_if_known is True).
-	"""
+def labgym_version_with_hash() -> str:
+	"""Return a hash-embellished version string for LabGym."""
 
 	hashval: str = get_hashval(labgym_package_folder)
 
 	version_with_longhash = f'{version} ({hashval})'
 	logger.debug('%s: %r', 'version_with_longhash', version_with_longhash)
 
-	if (suppress_if_known == True
-		and version_with_longhash in _get_known_versions()):
-			result = version  # without hashval
-	elif maxlen is not None:
-		result = f'{version} ({hashval[:maxlen]})'
-	else:
-		result = version_with_longhash
-
-	logger.debug('%s: %r', 'result', result)
-	return result
+	return version_with_longhash
diff --git a/LabGym/pkghash/versions.toml b/LabGym/pkghash/versions.toml
deleted file mode 100644
index df83357b..00000000
--- a/LabGym/pkghash/versions.toml
+++ /dev/null
@@ -1,3 +0,0 @@
-known_versions = [
-    '2.9.6 (d41d8cd98f00b204e9800998ecf8427e)',
-]
diff --git a/LabGym/probes.py b/LabGym/probes.py
index 1a32cab6..7ff92f83 100644
--- a/LabGym/probes.py
+++ b/LabGym/probes.py
@@ -171,8 +171,7 @@ def get_context(anonymous: bool=False) -> dict:
 	except Exception:
 		reginfo_uuid = None
 
-	version_with_hash = pkghash.labgym_version_with_hash(
-		maxlen=None, suppress_if_known=False)
+	version_with_hash = pkghash.labgym_version_with_hash()
 
 	result = {
 		'schema': 'context 2025-08-10',

From a8f10f759ce33138dd6e30974f26c2fa8e7f9d8a Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Thu, 8 Jan 2026 20:27:50 -0800
Subject: [PATCH 08/14] Update a myargparse.py unit test.

---
 LabGym/tests/test_myargparse.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/LabGym/tests/test_myargparse.py b/LabGym/tests/test_myargparse.py
index a4fcb9be..b4cc31d7 100644
--- a/LabGym/tests/test_myargparse.py
+++ b/LabGym/tests/test_myargparse.py
@@ -5,7 +5,7 @@
 import pytest
 
 from LabGym import myargparse
-from LabGym import __version__ as version
+from LabGym import __version__
 from .exitstatus import exitstatus
 
 
@@ -89,13 +89,17 @@ def test_parse_args_version(monkeypatch, capsys):
 	# Arrange
 	monkeypatch.setattr(sys, 'argv',
 		['cmd', '--version'])
+	hashval = '4cf004ad24fce8272bfda213219707d5'
+	version_with_hash = f'{__version__} ({hashval})'
+	monkeypatch.setattr(myargparse.pkghash, 'labgym_version_with_hash',
+		lambda: version_with_hash)
 
 	# Act, and assert raises(SystemExit)
 	with pytest.raises(SystemExit) as e:
 		result = myargparse.parse_args()
 
 	# Assert
-	assert capsys.readouterr().out == f'version: {version}\n'
+	assert capsys.readouterr().out == f'version: {version_with_hash}\n'
 	assert exitstatus(e.value) == 0
 
 

From 5c36cc663e48f4726e4b5f4032a2752b9f3de6df Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Fri, 9 Jan 2026 10:19:23 -0800
Subject: [PATCH 09/14] Instrument test_load.py and remove cwd assumption.

---
 tests/test_load.py | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/tests/test_load.py b/tests/test_load.py
index 16696ff1..786bac75 100644
--- a/tests/test_load.py
+++ b/tests/test_load.py
@@ -30,9 +30,17 @@ def test_import_LabGym_package():
 	"""Load LabGym.__init__.py and get a list of submodules."""
 	import LabGym
 
+	# ?!
+	print(f'os.getcwd(): {os.getcwd()}')
+	print(f'LabGym.__file__: {LabGym.__file__!r}')
+	print(f'os.path.dirname(LabGym.__file__): {os.path.dirname(LabGym.__file__)!r}')
+	print(f'os.path.dirname(os.path.dirname(LabGym.__file__)): {os.path.dirname(os.path.dirname(LabGym.__file__))!r}')
+	# is cwd not relevant for this test?
+	# is cwd not repeatable for this test?
+
 	# Confirm the assumption that under pytest, cwd is LabGym package's
 	# parent dir (the repo dir).
-	assert os.getcwd() == os.path.dirname(os.path.dirname(LabGym.__file__))
+	# assert os.getcwd() == os.path.dirname(os.path.dirname(LabGym.__file__))
 
 	# Prepare a list of all submodule py-files in LabGym dir, but not subdirs.
 	pyfiles = glob.glob(os.path.join(os.path.dirname(LabGym.__file__), '*.py'))
@@ -47,6 +55,9 @@ def test_import_LabGym_package():
 	# of this in this test.
 	submodules.remove('__init__')
 
+	# Add subpackages?
+	submodules.extend(['detectron2', 'mywx', 'pkghash', 'selftest'])
+
 
 def test_imports_with_sysargv_initialized(monkeypatch):
 	"""Test that some module imports don't raise exceptions.

From ed558eec7a961c60966b2c0febf30ad894ce3284 Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Fri, 9 Jan 2026 10:55:16 -0800
Subject: [PATCH 10/14] Instrument unit test... where am I?

---
 tests/test_load.py | 62 ++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 51 insertions(+), 11 deletions(-)

diff --git a/tests/test_load.py b/tests/test_load.py
index 786bac75..491fb45e 100644
--- a/tests/test_load.py
+++ b/tests/test_load.py
@@ -18,6 +18,7 @@
 import importlib
 import logging
 import os
+from pathlib import Path
 import pprint
 import sys
 import textwrap
@@ -26,29 +27,65 @@
 submodules = []
 
 
-def test_import_LabGym_package():
+def list_dir_and_first_children(directory_path):
+	"""
+	Lists the contents of a directory and the contents of its first-generation children.
+
+	Args:
+		directory_path (str or Path): The path to the directory to inspect.
+	"""
+	base_path = Path(directory_path)
+	if not base_path.is_dir():
+		print(f"Error: {directory_path} is not a valid directory.")
+		return
+
+	print(f"--- Contents of Directory: {base_path} ---")
+
+	# List immediate contents of the base directory
+	immediate_contents = list(base_path.iterdir())
+	for item in immediate_contents:
+		print(f"- {item.name} ({'Directory' if item.is_dir() else 'File'})")
+
+	print(f"\n--- Contents of First-Generation Children ---")
+
+	# Iterate through immediate contents and list their children if they are directories
+	for item in immediate_contents:
+		if item.is_dir():
+			print(f"\n  --- Subdirectory: {item.name} ---")
+			for sub_item in item.iterdir():
+				print(f"  - {sub_item.name} ({'Directory' if sub_item.is_dir() else 'File'})")
+
+
+def test_import_LabGym_package(capsys):
 	"""Load LabGym.__init__.py and get a list of submodules."""
 	import LabGym
 
 	# ?!
-	print(f'os.getcwd(): {os.getcwd()}')
-	print(f'LabGym.__file__: {LabGym.__file__!r}')
-	print(f'os.path.dirname(LabGym.__file__): {os.path.dirname(LabGym.__file__)!r}')
-	print(f'os.path.dirname(os.path.dirname(LabGym.__file__)): {os.path.dirname(os.path.dirname(LabGym.__file__))!r}')
+	with capsys.disabled():
+		print(f'os.getcwd(): {os.getcwd()}')
+		print(f'LabGym.__file__: {LabGym.__file__!r}')
+		print(f'os.path.dirname(LabGym.__file__): {os.path.dirname(LabGym.__file__)!r}')
+		print(f'os.path.dirname(os.path.dirname(LabGym.__file__)): {os.path.dirname(os.path.dirname(LabGym.__file__))!r}')
 	# is cwd not relevant for this test?
 	# is cwd not repeatable for this test?
 
 	# Confirm the assumption that under pytest, cwd is LabGym package's
 	# parent dir (the repo dir).
-	# assert os.getcwd() == os.path.dirname(os.path.dirname(LabGym.__file__))
+	try:
+		assert os.getcwd() == os.path.dirname(os.path.dirname(LabGym.__file__))
+	except:
+		# if I'm not in LabGymRepo, where am I?  LabGymRepo's parent dir?
+		with capsys.disabled():
+			list_dir_and_first_children(os.getcwd())
+
 
 	# Prepare a list of all submodule py-files in LabGym dir, but not subdirs.
 	pyfiles = glob.glob(os.path.join(os.path.dirname(LabGym.__file__), '*.py'))
 	pyfiles.sort()  # result from glob.glob() isn't sorted
 	submodules.extend([os.path.basename(f).removesuffix('.py')
 		for f in pyfiles])
-	logging.debug('%s:\n%s', 'Milepost 0, submodules',
-		textwrap.indent(pprint.pformat(submodules), '  '))
+	# logging.debug('%s:\n%s', 'Milepost 0, submodules',
+	#     textwrap.indent(pprint.pformat(submodules), '  '))
 
 	# Remove __init__.py.  There's no need to challenge it, as it was
 	# already loaded by the "import LabGym" statement at the beginning
@@ -58,6 +95,9 @@ def test_import_LabGym_package():
 	# Add subpackages?
 	submodules.extend(['detectron2', 'mywx', 'pkghash', 'selftest'])
 
+	with capsys.disabled():
+		print(f"Milepost 0, submodules: {textwrap.indent(pprint.pformat(submodules), '  ')}")
+
 
 def test_imports_with_sysargv_initialized(monkeypatch):
 	"""Test that some module imports don't raise exceptions.
@@ -78,10 +118,10 @@ def test_imports_with_sysargv_initialized(monkeypatch):
 	submodules.remove('myargparse')
 
 
-def test_remainder():
+def test_remainder(capsys):
 	"""Test that imports for the remaining modules don't raise exceptions."""
-	logging.debug('%s:\n%s', 'Milepost 1, submodules',
-		textwrap.indent(pprint.pformat(submodules), '  '))
+	with capsys.disabled():
+		print(f"Milepost 1, submodules: {textwrap.indent(pprint.pformat(submodules), '  ')}")
 
 	while len(submodules) > 0:
 		submodule = submodules[0]

From a3e44837dd1196a6f52b294b5c539898dc3fd7ff Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Fri, 9 Jan 2026 11:36:34 -0800
Subject: [PATCH 11/14] Employ a context-manager to make chdir temporary.

---
 LabGym/pkghash/hash.py | 66 +++++++++++++++++++++++++-----------------
 1 file changed, 40 insertions(+), 26 deletions(-)

diff --git a/LabGym/pkghash/hash.py b/LabGym/pkghash/hash.py
index 77957f4d..6c8cd818 100644
--- a/LabGym/pkghash/hash.py
+++ b/LabGym/pkghash/hash.py
@@ -11,6 +11,7 @@
 from __future__ import annotations
 
 # Standard library imports.
+from contextlib import contextmanager
 import hashlib
 import itertools
 import logging
@@ -32,6 +33,19 @@
 _cached_hashvals = {}
 
 
+# from contextlib import chdir  # available in Python 3.11+
+# To support earlier Python, implement chdir
+@contextmanager
+def chdir(path):
+	"""Temporarily chdir."""
+	old_cwd = os.getcwd()
+	try:
+		os.chdir(path)
+		yield
+	finally:
+		os.chdir(old_cwd)  # restore
+
+
 def get_hashval(folder: str) -> str:
 	"""Return a hashval (a signature) of the contents of the folder.
 
@@ -74,34 +88,34 @@ def _walk_and_hash(folder: Path) -> str:
 	"""
 
 	hasher = hashlib.md5()
-	os.chdir(folder)
-
-	for root, dirs, files in os.walk('.'):
-		# walk in "sorted" order
-		dirs.sort()
-		files.sort()
-
-		# Skip dirs that don't have __init__.py.
-		if '__init__.py' not in files:
-			# this is not a "traditional" package dir...
-			# skip further descent
-			dirs.clear()
-			# skip processing files in this dir
-			continue
-
-		# Skip top-level dirs detectron2, detectors, models.
-		if root == '.':
-			for name in ['detectron2', 'detectors', 'models']:
-				if name in dirs:
-					dirs.remove(name)
-
-		for file in files:
-			# Skip non-py-files.
-			if not file.endswith('.py'):
+
+	with chdir(folder):
+		for root, dirs, files in os.walk('.'):
+			# walk in "sorted" order
+			dirs.sort()
+			files.sort()
+
+			# Skip dirs that don't have __init__.py.
+			if '__init__.py' not in files:
+				# this is not a "traditional" package dir...
+				# skip further descent
+				dirs.clear()
+				# skip processing files in this dir
 				continue
 
-			file_path = os.path.join(root, file)
-			_add_file_to_hash(hasher, file_path)
+			# Skip top-level dirs detectron2, detectors, models.
+			if root == '.':
+				for name in ['detectron2', 'detectors', 'models']:
+					if name in dirs:
+						dirs.remove(name)
+
+			for file in files:
+				# Skip non-py-files.
+				if not file.endswith('.py'):
+					continue
+
+				file_path = os.path.join(root, file)
+				_add_file_to_hash(hasher, file_path)
 
 	hashval = hasher.hexdigest()
 	logger.debug('%s: %r', 'hashval', hashval)

From 029c52f432cd4946c6410d2b8c3126b53398ec29 Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Fri, 9 Jan 2026 11:58:56 -0800
Subject: [PATCH 12/14] In hash.py, open files for hash with encoding
 specified, for Windws!

---
 LabGym/pkghash/hash.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/LabGym/pkghash/hash.py b/LabGym/pkghash/hash.py
index 6c8cd818..08cf2e05 100644
--- a/LabGym/pkghash/hash.py
+++ b/LabGym/pkghash/hash.py
@@ -145,7 +145,7 @@ def _add_file_to_hash(hasher, file_path: str) -> None:
 		#     while chunk := f.read(8192):
 		#         hasher.update(chunk)
 
-		with open(file_path, 'r') as f:
+		with open(file_path, 'r', encoding='utf-8') as f:
 			# Read file in 200-line chunks to handle large files efficiently
 			for chunk in _myreadlines(f):
 				for i, line in enumerate(chunk):

From de49a7cc82e57e58e892f6d519d632323091f377 Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Fri, 9 Jan 2026 12:23:20 -0800
Subject: [PATCH 13/14] Scrub excess instrumentation from test_load.py.

---
 tests/test_load.py | 68 ++++++++++------------------------------------
 1 file changed, 15 insertions(+), 53 deletions(-)

diff --git a/tests/test_load.py b/tests/test_load.py
index 491fb45e..25f9fdda 100644
--- a/tests/test_load.py
+++ b/tests/test_load.py
@@ -27,77 +27,39 @@
 submodules = []
 
 
-def list_dir_and_first_children(directory_path):
-	"""
-	Lists the contents of a directory and the contents of its first-generation children.
-
-	Args:
-		directory_path (str or Path): The path to the directory to inspect.
-	"""
-	base_path = Path(directory_path)
-	if not base_path.is_dir():
-		print(f"Error: {directory_path} is not a valid directory.")
-		return
-
-	print(f"--- Contents of Directory: {base_path} ---")
-
-	# List immediate contents of the base directory
-	immediate_contents = list(base_path.iterdir())
-	for item in immediate_contents:
-		print(f"- {item.name} ({'Directory' if item.is_dir() else 'File'})")
-
-	print(f"\n--- Contents of First-Generation Children ---")
-
-	# Iterate through immediate contents and list their children if they are directories
-	for item in immediate_contents:
-		if item.is_dir():
-			print(f"\n  --- Subdirectory: {item.name} ---")
-			for sub_item in item.iterdir():
-				print(f"  - {sub_item.name} ({'Directory' if sub_item.is_dir() else 'File'})")
-
-
 def test_import_LabGym_package(capsys):
 	"""Load LabGym.__init__.py and get a list of submodules."""
 	import LabGym
 
-	# ?!
-	with capsys.disabled():
-		print(f'os.getcwd(): {os.getcwd()}')
-		print(f'LabGym.__file__: {LabGym.__file__!r}')
-		print(f'os.path.dirname(LabGym.__file__): {os.path.dirname(LabGym.__file__)!r}')
-		print(f'os.path.dirname(os.path.dirname(LabGym.__file__)): {os.path.dirname(os.path.dirname(LabGym.__file__))!r}')
-	# is cwd not relevant for this test?
-	# is cwd not repeatable for this test?
-
 	# Confirm the assumption that under pytest, cwd is LabGym package's
 	# parent dir (the repo dir).
-	try:
-		assert os.getcwd() == os.path.dirname(os.path.dirname(LabGym.__file__))
-	except:
-		# if I'm not in LabGymRepo, where am I?  LabGymRepo's parent dir?
-		with capsys.disabled():
-			list_dir_and_first_children(os.getcwd())
-
+	# The assumption isn't strictly necessary for these unit tests, but
+	# a failed assert would indicate either (a) noxfile.py was moved
+	# (the starting cwd is same as location of noxfile.py), or, (b) some
+	# other unit test in the session did a chdir (possibly by exercising
+	# code that used an os.chdir instead of a contextlib.chdir).
+	assert os.getcwd() == os.path.dirname(os.path.dirname(LabGym.__file__))
 
 	# Prepare a list of all submodule py-files in LabGym dir, but not subdirs.
 	pyfiles = glob.glob(os.path.join(os.path.dirname(LabGym.__file__), '*.py'))
 	pyfiles.sort()  # result from glob.glob() isn't sorted
 	submodules.extend([os.path.basename(f).removesuffix('.py')
 		for f in pyfiles])
-	# logging.debug('%s:\n%s', 'Milepost 0, submodules',
-	#     textwrap.indent(pprint.pformat(submodules), '  '))
 
 	# Remove __init__.py.  There's no need to challenge it, as it was
 	# already loaded by the "import LabGym" statement at the beginning
-	# of this in this test.
+	# of this in this test.  And furthermore, as it is already loaded,
+	# importing it (again) would not reload it.  OTOH, if it wasn't
+	# specifically removed here, there would be no harm done.
 	submodules.remove('__init__')
 
-	# Add subpackages?
+	# Add subpackages?  This requires maintenance... find subdirs with
+	# py-files and load them?  Loading the package doesn't necessarily
+	# load all of the package's py-files... (that's why we are
+	# attempting to load all of LabGym package's first-generation
+	# py-files)
 	submodules.extend(['detectron2', 'mywx', 'pkghash', 'selftest'])
 
-	with capsys.disabled():
-		print(f"Milepost 0, submodules: {textwrap.indent(pprint.pformat(submodules), '  ')}")
-
 
 def test_imports_with_sysargv_initialized(monkeypatch):
 	"""Test that some module imports don't raise exceptions.
@@ -121,7 +83,7 @@ def test_imports_with_sysargv_initialized(monkeypatch):
 def test_remainder(capsys):
 	"""Test that imports for the remaining modules don't raise exceptions."""
 	with capsys.disabled():
-		print(f"Milepost 1, submodules: {textwrap.indent(pprint.pformat(submodules), '  ')}")
+		print(f"submodules: {textwrap.indent(pprint.pformat(submodules), '  ')}")
 
 	while len(submodules) > 0:
 		submodule = submodules[0]

From d235c0f1725c5f272c6464759e36adf52d98cd00 Mon Sep 17 00:00:00 2001
From: ruck94301 <John.Ruckstuhl@gmail.com>
Date: Fri, 9 Jan 2026 13:52:23 -0800
Subject: [PATCH 14/14] Add unit-test of pkghash

---
 LabGym/tests/test_pkghash.py | 10 ++++++
 tests/test_load.py           | 62 +++++++++++++++++++++++++++++-------
 2 files changed, 60 insertions(+), 12 deletions(-)
 create mode 100644 LabGym/tests/test_pkghash.py

diff --git a/LabGym/tests/test_pkghash.py b/LabGym/tests/test_pkghash.py
new file mode 100644
index 00000000..26563c2b
--- /dev/null
+++ b/LabGym/tests/test_pkghash.py
@@ -0,0 +1,10 @@
+from LabGym import pkghash
+
+def test_pkghash(capsys):
+	# Arrange
+	# Act
+	version_with_hash = pkghash.labgym_version_with_hash()
+	# Assert
+
+	with capsys.disabled():
+		print('\n' f'version_with_hash: {version_with_hash}')
diff --git a/tests/test_load.py b/tests/test_load.py
index 25f9fdda..2333da76 100644
--- a/tests/test_load.py
+++ b/tests/test_load.py
@@ -9,9 +9,10 @@
 
 The final test, test_remainder(), imports each of the remaining top-
 level py-files.
+
 The strength of this catch-all final test is that if a new top-level
 py-file is introduced, full coverage is preserved and this test-file
-may still be suitable.
+may not require updating.
 """
 
 import glob
@@ -23,23 +24,60 @@
 import sys
 import textwrap
 
+import LabGym
 
 submodules = []
 
 
-def test_import_LabGym_package(capsys):
-	"""Load LabGym.__init__.py and get a list of submodules."""
-	import LabGym
-
-	# Confirm the assumption that under pytest, cwd is LabGym package's
-	# parent dir (the repo dir).
-	# The assumption isn't strictly necessary for these unit tests, but
-	# a failed assert would indicate either (a) noxfile.py was moved
-	# (the starting cwd is same as location of noxfile.py), or, (b) some
-	# other unit test in the session did a chdir (possibly by exercising
-	# code that used an os.chdir instead of a contextlib.chdir).
+def test_cwd():
+	"""
+	Test that cwd is the LabGym package's parent dir (the repo dir).
+
+	This condition isn't strictly necessary for these unit tests, but a
+	a failed assert would indicate either (a) noxfile.py was moved (the
+	starting cwd is same as location of noxfile.py), or, (b) some other
+	unit test in the session did a chdir (possibly by exercising code
+	that used an os.chdir instead of a contextlib.chdir).
+
+	As currently organized, the repo dir contains noxfile.py and the
+	Labgym package dir.
+
+	"In github running nox on a PR commit, what is my cwd? Is it my
+	repo dir?"
+
+	Google AI Overview responds:
+		When running Nox in a GitHub Actions workflow on a PR commit, your
+		current working directory (cwd) is the root of your repository on
+		the runner's machine.
+
+		The working directory in GitHub Actions is a specific path on the
+		runner, typically /home/runner/work/<repo>/<repo> on Linux, which is
+		where the actions/checkout action places your code by default.
+
+		Nox itself also has a default behavior: it automatically changes its
+		working directory to the directory containing the noxfile.py script
+		before running any sessions.
+
+		Therefore:
+		*   The initial working directory for the GitHub Actions step
+			running Nox is the repository root.
+		*   Once the nox command executes, the working directory for the
+			individual Nox sessions (the Python functions in your
+			noxfile.py) will be the directory where the noxfile.py is
+			located.
+
+		This means you can generally rely on paths within your Nox sessions
+		being relative to the noxfile.py location, which is usually at the
+		root of your repository (unless you've specified a different
+		location in your workflow or using the --noxfile argument).
+	"""
+	assert os.path.isfile('noxfile.py')
 	assert os.getcwd() == os.path.dirname(os.path.dirname(LabGym.__file__))
 
+
+def test_import_LabGym_package():
+	"""Load LabGym.__init__.py and get a list of submodules."""
+
 	# Prepare a list of all submodule py-files in LabGym dir, but not subdirs.
 	pyfiles = glob.glob(os.path.join(os.path.dirname(LabGym.__file__), '*.py'))
 	pyfiles.sort()  # result from glob.glob() isn't sorted