diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4f985e9..68f2398 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -3,10 +3,10 @@ name: CI
 on:
   push:
     branches:
-      - boilerplate
+      - master
       - dev
+      - boilerplate
       - idiomatic
-      - master
       - rc1
       - rc2
       - rc3
diff --git a/.vimrc b/.vimrc
new file mode 100644
index 0000000..1bf33a0
--- /dev/null
+++ b/.vimrc
@@ -0,0 +1,70 @@
+" Synesis C/C++ project .vimrc — aligned with .sis/.vscode/c_cxx/settings.json
+
+set nocompatible
+filetype indent plugin on
+syntax enable
+set autoindent
+set backspace=indent,eol,start
+set hlsearch
+set incsearch
+set number
+
+" files.insertFinalNewline
+set eol
+set fixeol
+
+" editor.renderWhitespace: all
+set list
+set listchars=tab:->,trail:-,extends:>,precedes:<,nbsp:+
+
+" editor.detectIndentation: false — global defaults (editor.tabSize: 4, insertSpaces: true)
+set colorcolumn=76
+set expandtab
+set shiftwidth=4
+set softtabstop=4
+set tabstop=4
+
+" colorcolumn draws a full-column tint in Vim (not a VS Code-style 1px line).
+" Keep it subtle via the ColorColumn highlight group; reapply after colorscheme changes.
+if has('termguicolors')
+  " set termguicolors
+endif
+
+function! s:ConfigureColorColumn() abort
+  highlight ColorColumn ctermbg=236 guibg=#2a2a2a cterm=NONE gui=NONE
+endfunction
+
+call s:ConfigureColorColumn()
+autocmd ColorScheme * call s:ConfigureColorColumn()
+
+" files.trimTrailingWhitespace
+autocmd BufWritePre * %s/\s\+$//e
+
+augroup sis_c_cxx
+  autocmd!
+
+  " [c] / [cpp]
+  autocmd FileType c,cpp setlocal expandtab tabstop=4 shiftwidth=4 softtabstop=4 colorcolumn=60,64,68,72,76
+
+  " [rust]
+  autocmd FileType rs setlocal expandtab tabstop=4 shiftwidth=4 softtabstop=4 colorcolumn=76
+
+  " [cmake]
+  autocmd FileType cmake setlocal noexpandtab tabstop=4 shiftwidth=4 softtabstop=4
+
+  " [shellscript]
+  autocmd FileType sh,bash,zsh setlocal expandtab tabstop=2 shiftwidth=2 softtabstop=2 colorcolumn=60,76
+
+  " [bat]
+  autocmd FileType bat,dosbatch setlocal expandtab tabstop=4 shiftwidth=4 softtabstop=4 colorcolumn=60,76
+
+  " [json] / [markdown] / [yaml] / [ruby]
+  autocmd FileType json,markdown,yaml,ruby setlocal expandtab tabstop=2 shiftwidth=2 softtabstop=2
+
+  " [python]
+  autocmd FileType python setlocal expandtab tabstop=4 shiftwidth=4 softtabstop=4 colorcolumn=60,76
+
+  " [toml]
+  autocmd FileType toml setlocal noexpandtab tabstop=2 shiftwidth=2 softtabstop=2
+augroup END
+
diff --git a/CHANGES.md b/CHANGES.md
index 0bc7be0..1849ef6 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,6 +1,15 @@
 # Pantheios.Extras.AtExit - Changes <!-- omit in toc -->
 
 
+## 0.1.2-alpha1 - 21st August 2026
+
+* Modernised library version macros to computed `PANTHEIOS_EXTRAS_ATEXIT_VER` (`VER_MAJOR` / `VER_MINOR` / `VER_PATCH` / `VER_ALPHABETA`, with `VER_REVISION` alias) targeting **0.1.2-alpha1**;
+* Added **ctest_cmake.sh** and **run_all_unit_tests.cmd**;
+* Ensured C/C++ sources end with a blank line after the end-of-file marker, and used `char* argv[]` in the unit-test `main`;
+* Renamed the scratch program implementation to **main.c**;
+* Recorded functionality-review items in **TODO.md**; deferred applying them, and deferred the helper **MSYSTEM**/MinGW rewrite until the **HELPER-SCRIPTS-C-CXX.md** contract is frozen;
+
+
 ## 0.1.1 - 16th August 2026
 
 * Recovered **Pantheios.Extras.AtExit** from Hautacam (`pantheios/extras/AtExit/0.1`, Created 30th December 2011) as a nested compiled C library;
diff --git a/NEWS.md b/NEWS.md
index fad4113..6ded513 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -10,6 +10,7 @@
 
 | Date             | News Item                                                                        |
 | ---------------- | -------------------------------------------------------------------------------- |
+| 21st August 2026 | Pantheios.Extras.AtExit 0.1.2-alpha1                                             |
 | 16th August 2026 | Pantheios.Extras.AtExit 0.1.1 recovered and released                             |
 
 
diff --git a/TODO.md b/TODO.md
index 4d4c98b..763afa2 100644
--- a/TODO.md
+++ b/TODO.md
@@ -3,6 +3,30 @@
 
 ## Functional improvements
 
+
+### High
+
+* [ ] Document (and optionally enforce) **`add` after `uninit`**: the libc `atexit` hook stays registered, so later **`add`** callbacks still run at process exit; docs currently imply the hook is a permanent no-op after drain;
+* [ ] Document (or change) drain-while-locked: callbacks run under the spinlock, so a callback that calls **`add`** / **`uninit`** deadlocks; either forbid re-entrancy or copy the list, unlock, then invoke;
+
+
+### Medium
+
+* [ ] Serialise **`init`**: `s_initialised` is a plain `int` and `init` is not under the lock, so two threads can register two `atexit` hooks;
+* [ ] Align **`reserved0`** / **`reserved1`**: header says they must be `NULL` / `0`, but the implementation ignores them — `assert` or drop the requirement;
+* [ ] Stop treating **`atexit()`** failure as an `errno` / **`strerror()`** code; `EBUSY` / `ENOMEM` are errno values, `atexit` failure often is not;
+
+
+### Low
+
+* [ ] Document **`add` without `init`**: the list grows, but process exit will not drain it unless **`uninit`** is called;
+* [ ] Initialise C11 `atomic_int s_mx` with **`ATOMIC_VAR_INIT(0)`** if compilers warn on `= 0`;
+* [ ] Tests: **`add`** without **`init`** then **`uninit`**; **`add`** after **`uninit`**; version-macro unit test; keep process-exit coverage as scratch (or one automated case);
+* [ ] Example: check **`add`** return values;
+
+
+### Enhancements
+
 * [ ] C++ RAII / `scope` wrapper;
 * [ ] Unix-only pthread synchronisation scratch (with a Windows equivalent if revived);
 
@@ -14,7 +38,8 @@
 
 ## Packaging improvements
 
-* \<none>
+* [ ] Defer rewriting helper `MSYSTEM` → `mingw32-make` / MinGW-generator detection until the **HELPER-SCRIPTS-C-CXX.md** contract is frozen (same defect class as other Synesis C/C++ helpers);
+* [ ] Split the unit-test implementation from its entry TU (then name the entry **entry.c**); until then keep the single-file **test.unit.atexit.api.c**;
 
 
 <!-- ########################### end of file ########################### -->
diff --git a/ctest_cmake.sh b/ctest_cmake.sh
new file mode 100755
index 0000000..24c2172
--- /dev/null
+++ b/ctest_cmake.sh
@@ -0,0 +1,108 @@
+#! /bin/bash
+
+ScriptPath=$0
+Dir=$(cd $(dirname "$ScriptPath"); pwd)
+Basename=$(basename "$ScriptPath")
+CMakeDir=${SIS_CMAKE_BUILD_DIR:-$Dir/_build}
+[[ -n "$MSYSTEM" ]] && DefaultMakeCmd=mingw32-make.exe || DefaultMakeCmd=make
+MakeCmd=${SIS_CMAKE_MAKE_COMMAND:-${SIS_CMAKE_COMMAND:-$DefaultMakeCmd}}
+ProjectNameFile="$Dir/.sis/project_name.txt"
+ProjectName=$(tr -d '[:space:]' < "$ProjectNameFile")
+
+CMakeVerbose=
+RunMake=1
+
+
+# ##########################################################
+# command-line handling
+
+while [[ $# -gt 0 ]]; do
+
+  case $1 in
+    --no-make|-M)
+
+      RunMake=0
+      ;;
+    --verbose|-V)
+
+      CMakeVerbose=--verbose
+      ;;
+    --help)
+
+      [ -f "$Dir/.sis/script_info_lines.txt" ] && cat "$Dir/.sis/script_info_lines.txt"
+      cat << EOF
+Runs CMake's CTest test program(s)
+
+$ScriptPath [ ... flags/options ... ]
+
+Flags/options:
+
+    behaviour:
+
+    -M
+    --no-make
+        does not execute CMake and make before running tests
+
+    -V
+    --verbose
+        verbose test output
+
+
+    standard flags:
+
+    --help
+        displays this help and terminates
+
+EOF
+
+      exit 0
+      ;;
+    *)
+
+      >&2 echo "$ScriptPath: unrecognised argument '$1'; use --help for usage"
+
+      exit 1
+      ;;
+  esac
+
+  shift
+done
+
+
+# ##########################################################
+# main()
+
+status=0
+
+if [ $RunMake -ne 0 ]; then
+
+  echo "Executing build for ${ProjectName} (via command \`$MakeCmd\`) and then running all component and unit test programs"
+
+  mkdir -p $CMakeDir || exit 1
+
+  cd $CMakeDir
+
+  $MakeCmd
+  status=$?
+
+  cd ->/dev/null
+else
+
+  if [ ! -d "$CMakeDir" ] || [ ! -f "$CMakeDir/CMakeCache.txt" ] || [ ! -d "$CMakeDir/CMakeFiles" ]; then
+
+    >&2 echo "$ScriptPath: cannot run in '--no-make' mode without a previous successful build step"
+  fi
+fi
+
+if [ $status -eq 0 ]; then
+
+  echo "Running CMake tests"
+
+  ctest --test-dir $CMakeDir $CMakeVerbose
+  status=$?
+fi
+
+exit $status
+
+
+# ############################## end of file ############################# #
diff --git a/examples/c/example.c.1/example.c.1.c b/examples/c/example.c.1/example.c.1.c
index 56b4978..3b43bd0 100644
--- a/examples/c/example.c.1/example.c.1.c
+++ b/examples/c/example.c.1/example.c.1.c
@@ -37,10 +37,18 @@ main(void)
 
     if (0 != r)
     {
+#ifdef _MSC_VER
+        char error_message[256];
+
+        strerror_s(error_message, sizeof(error_message), r);
+#else
+        char const* error_message = strerror(r);
+#endif
+
         fprintf(
             stderr
         ,   "failed to initialise Pantheios.Extras.AtExit : %s (%d)\n"
-        ,   strerror(r)
+        ,   error_message
         ,   r
         );
 
@@ -60,3 +68,4 @@ main(void)
 
 
 /* ///////////////////////////// end of file //////////////////////////// */
+
diff --git a/include/pantheios/extras/atexit.h b/include/pantheios/extras/atexit.h
index e708ff5..4f75829 100644
--- a/include/pantheios/extras/atexit.h
+++ b/include/pantheios/extras/atexit.h
@@ -4,7 +4,7 @@
  * Purpose:     Main C header for the Pantheios.Extras.AtExit library.
  *
  * Created:     30th December 2011
- * Updated:     16th August 2026
+ * Updated:     21st August 2026
  *
  * Home:        http://www.pantheios.org/
  *
@@ -55,8 +55,8 @@
 #ifndef PANTHEIOS_DOCUMENTATION_SKIP_SECTION
 # define PANTHEIOS_EXTRAS_ATEXIT_VER_PANTHEIOS_EXTRAS_H_ATEXIT_MAJOR    1
 # define PANTHEIOS_EXTRAS_ATEXIT_VER_PANTHEIOS_EXTRAS_H_ATEXIT_MINOR    0
-# define PANTHEIOS_EXTRAS_ATEXIT_VER_PANTHEIOS_EXTRAS_H_ATEXIT_REVISION 3
-# define PANTHEIOS_EXTRAS_ATEXIT_VER_PANTHEIOS_EXTRAS_H_ATEXIT_EDIT     4
+# define PANTHEIOS_EXTRAS_ATEXIT_VER_PANTHEIOS_EXTRAS_H_ATEXIT_REVISION 4
+# define PANTHEIOS_EXTRAS_ATEXIT_VER_PANTHEIOS_EXTRAS_H_ATEXIT_EDIT     5
 #endif /* !PANTHEIOS_DOCUMENTATION_SKIP_SECTION */
 
 /* /////////////////////////////////////////////////////////////////////////
@@ -76,3 +76,4 @@
 #endif /* !PANTHEIOS_EXTRAS_ATEXIT_INCL_PANTHEIOS_EXTRAS_H_ATEXIT */
 
 /* ///////////////////////////// end of file //////////////////////////// */
+
diff --git a/include/pantheios/extras/atexit/atexit.h b/include/pantheios/extras/atexit/atexit.h
index a478ae7..d6dd9e4 100644
--- a/include/pantheios/extras/atexit/atexit.h
+++ b/include/pantheios/extras/atexit/atexit.h
@@ -4,7 +4,7 @@
  * Purpose:     Header file for Pantheios.Extras.AtExit.
  *
  * Created:     30th December 2011
- * Updated:     16th August 2026
+ * Updated:     21st August 2026
  *
  * Home:        http://www.pantheios.org/
  *
@@ -54,9 +54,9 @@
 
 #ifndef PANTHEIOS_DOCUMENTATION_SKIP_SECTION
 # define PANTHEIOS_EXTRAS_ATEXIT_VER_PANTHEIOS_EXTRAS_ATEXIT_H_ATEXIT_MAJOR    1
-# define PANTHEIOS_EXTRAS_ATEXIT_VER_PANTHEIOS_EXTRAS_ATEXIT_H_ATEXIT_MINOR    1
-# define PANTHEIOS_EXTRAS_ATEXIT_VER_PANTHEIOS_EXTRAS_ATEXIT_H_ATEXIT_REVISION 1
-# define PANTHEIOS_EXTRAS_ATEXIT_VER_PANTHEIOS_EXTRAS_ATEXIT_H_ATEXIT_EDIT     5
+# define PANTHEIOS_EXTRAS_ATEXIT_VER_PANTHEIOS_EXTRAS_ATEXIT_H_ATEXIT_MINOR    2
+# define PANTHEIOS_EXTRAS_ATEXIT_VER_PANTHEIOS_EXTRAS_ATEXIT_H_ATEXIT_REVISION 0
+# define PANTHEIOS_EXTRAS_ATEXIT_VER_PANTHEIOS_EXTRAS_ATEXIT_H_ATEXIT_EDIT     6
 #endif /* !PANTHEIOS_DOCUMENTATION_SKIP_SECTION */
 
 /** \def PANTHEIOS_EXTRAS_ATEXIT_VER_MAJOR
@@ -67,23 +67,43 @@
  * The minor version number of Pantheios.Extras.AtExit
  */
 
-/** \def PANTHEIOS_EXTRAS_ATEXIT_VER_REVISION
- * The revision version number of Pantheios.Extras.AtExit
+/** \def PANTHEIOS_EXTRAS_ATEXIT_VER_PATCH
+ * The patch version number of Pantheios.Extras.AtExit
+ */
+
+/** \def PANTHEIOS_EXTRAS_ATEXIT_VER_ALPHABETA
+ * The alpha/beta designator of Pantheios.Extras.AtExit, or 0xFF for a
+ * non-prerelease
  */
 
 /** \def PANTHEIOS_EXTRAS_ATEXIT_VER
  * The current composite version number of Pantheios.Extras.AtExit
  */
 
+/** \def PANTHEIOS_EXTRAS_ATEXIT_VER_REVISION
+ * Alias of PANTHEIOS_EXTRAS_ATEXIT_VER_PATCH (for CMake scrapers / older
+ * consumers)
+ */
+
 #ifndef PANTHEIOS_DOCUMENTATION_SKIP_SECTION
 # define PANTHEIOS_EXTRAS_ATEXIT_VER_0_1_1                     0x000101ff
+# define PANTHEIOS_EXTRAS_ATEXIT_VER_0_1_2_ALPHA_1             0x00010241
 #endif /* !PANTHEIOS_DOCUMENTATION_SKIP_SECTION */
 
 #define PANTHEIOS_EXTRAS_ATEXIT_VER_MAJOR                     0
 #define PANTHEIOS_EXTRAS_ATEXIT_VER_MINOR                     1
-#define PANTHEIOS_EXTRAS_ATEXIT_VER_REVISION                  1
+#define PANTHEIOS_EXTRAS_ATEXIT_VER_PATCH                     2
+#define PANTHEIOS_EXTRAS_ATEXIT_VER_ALPHABETA                 0x41
 
-#define PANTHEIOS_EXTRAS_ATEXIT_VER                           PANTHEIOS_EXTRAS_ATEXIT_VER_0_1_1
+#define PANTHEIOS_EXTRAS_ATEXIT_VER \
+    (0\
+        |   (   PANTHEIOS_EXTRAS_ATEXIT_VER_MAJOR       << 24   ) \
+        |   (   PANTHEIOS_EXTRAS_ATEXIT_VER_MINOR       << 16   ) \
+        |   (   PANTHEIOS_EXTRAS_ATEXIT_VER_PATCH       <<  8   ) \
+        |   (   PANTHEIOS_EXTRAS_ATEXIT_VER_ALPHABETA   <<  0   ) \
+    )
+
+#define PANTHEIOS_EXTRAS_ATEXIT_VER_REVISION                  PANTHEIOS_EXTRAS_ATEXIT_VER_PATCH
 
 #ifdef __cplusplus
 extern "C" {
@@ -165,3 +185,4 @@ pantheios_extras_atexit_add(
 #endif /* !PANTHEIOS_EXTRAS_ATEXIT_INCL_PANTHEIOS_EXTRAS_ATEXIT_H_ATEXIT */
 
 /* ///////////////////////////// end of file //////////////////////////// */
+
diff --git a/run_all_unit_tests.cmd b/run_all_unit_tests.cmd
new file mode 100644
index 0000000..b68c97e
--- /dev/null
+++ b/run_all_unit_tests.cmd
@@ -0,0 +1,188 @@
+@echo off
+
+SETLOCAL ENABLEEXTENSIONS ENABLEDELAYEDEXPANSION
+
+SET SCRIPT_DIRECTORY=%~dp0
+SET SCRIPT_PATH_DOC=%~n0[%~x0]
+IF DEFINED SIS_CMAKE_BUILD_DIR (
+
+	SET "CMAKE_DIR=%SIS_CMAKE_BUILD_DIR%"
+) ELSE (
+
+	SET "CMAKE_DIR=%SCRIPT_DIRECTORY%_build"
+)
+
+SET ListOnly=0
+SET Verbose=0
+SET UnitOnly=0
+SET ComponentOnly=0
+SET status=0
+
+FOR %%a IN (%*) DO (
+	IF /I {--help}=={%%a} (
+		IF EXIST "%SCRIPT_DIRECTORY%.sis\script_info_lines.txt" (
+
+			type "%SCRIPT_DIRECTORY%.sis\script_info_lines.txt"
+		)
+		ECHO ^
+
+Runs all ^(matching^) unit-test and/or component-test programs ^
+
+^
+
+%SCRIPT_PATH_DOC% [ ... flags/options ... ] ^
+
+^
+
+Flags/options: ^
+
+    behaviour: ^
+
+^
+
+    -l ^
+
+    --list-only ^
+
+        lists the target programs but does not execute them ^
+
+^
+
+    -M ^
+
+    --no-make ^
+
+        accepted for parity with the .sh script ^(build is not invoked^) ^
+
+^
+
+    --unit-only ^
+
+        runs only unit-test programs ^(test.unit.* / test_unit*^) ^
+
+^
+
+    --component-only ^
+
+        runs only component-test programs ^(test.component.* / test_component*^) ^
+
+^
+
+    -v ^
+
+    --verbose ^
+
+        lists each test program before executing it ^
+
+^
+
+    standard flags: ^
+
+^
+
+        --help ^
+
+            displays this help and terminates ^
+
+
+		EXIT /B 0
+	) ELSE IF /I {-l}=={%%a} (
+		SET ListOnly=1
+	) ELSE IF /I {--list-only}=={%%a} (
+		SET ListOnly=1
+	) ELSE IF /I {-M}=={%%a} (
+		REM no-op: this .cmd never invokes the build
+	) ELSE IF /I {--no-make}=={%%a} (
+		REM no-op: this .cmd never invokes the build
+	) ELSE IF /I {--unit-only}=={%%a} (
+		SET UnitOnly=1
+	) ELSE IF /I {--component-only}=={%%a} (
+		SET ComponentOnly=1
+	) ELSE IF /I {-v}=={%%a} (
+		SET Verbose=1
+	) ELSE IF /I {--verbose}=={%%a} (
+		SET Verbose=1
+	) ELSE (
+		ECHO %SCRIPT_PATH_DOC%: unrecognised argument '%%a'; use --help for usage 1>&2
+
+		EXIT /B 1
+	)
+)
+
+IF !UnitOnly! EQU 1 IF !ComponentOnly! EQU 1 (
+
+	ECHO %SCRIPT_PATH_DOC%: --unit-only and --component-only are mutually exclusive 1>&2
+
+	EXIT /B 1
+)
+
+IF NOT EXIST "%CMAKE_DIR%" (
+
+	ECHO %SCRIPT_PATH_DOC%: CMake build directory '%CMAKE_DIR%' does not exist 1>&2
+
+	EXIT /B 1
+)
+
+SET "ProjectName="
+FOR /F "usebackq delims=" %%p IN ("%SCRIPT_DIRECTORY%.sis\project_name.txt") DO SET "ProjectName=%%p"
+
+IF NOT DEFINED ProjectName (
+
+	ECHO %SCRIPT_PATH_DOC%: could not read project name from .sis\project_name.txt 1>&2
+
+	EXIT /B 1
+)
+
+IF !UnitOnly! EQU 1 (
+
+	SET "TestKindDescription=unit test"
+) ELSE IF !ComponentOnly! EQU 1 (
+
+	SET "TestKindDescription=component test"
+) ELSE (
+
+	SET "TestKindDescription=component and unit test"
+)
+
+IF !ListOnly! EQU 1 (
+
+	ECHO Listing all !ProjectName! !TestKindDescription! programs
+) ELSE (
+
+	ECHO Running all !ProjectName! !TestKindDescription! programs
+)
+
+IF !UnitOnly! EQU 1 (
+
+	SET "FindPattern=test\.unit\..*\.exe$"
+) ELSE IF !ComponentOnly! EQU 1 (
+
+	SET "FindPattern=test\.component\..*\.exe$"
+) ELSE (
+
+	SET "FindPattern=test\.unit\..*\.exe$ test\.component\..*\.exe$"
+)
+
+FOR /F "usebackq delims=" %%f IN (`DIR /A:-D /B /S "%CMAKE_DIR%\*.exe" 2^>NUL ^| FINDSTR /I /R "!FindPattern!"`) DO (
+	IF !ListOnly! EQU 1 (
+
+		ECHO would execute %%f:
+	) ELSE (
+
+		IF !Verbose! EQU 1 (
+
+			ECHO executing %%f:
+		)
+
+		"%%f"
+		IF ERRORLEVEL 1 (
+
+			SET status=1
+
+			GOTO :done
+		)
+	)
+)
+
+:done
+EXIT /B !status!
diff --git a/src/atexit.api.c b/src/atexit.api.c
index 65d9b2d..6c72c30 100644
--- a/src/atexit.api.c
+++ b/src/atexit.api.c
@@ -4,7 +4,7 @@
  * Purpose: Implementation file for Pantheios.Extras.AtExit
  *
  * Created: 30th December 2011
- * Updated: 16th August 2026
+ * Updated: 31st August 2026
  *
  * Home:    http://www.pantheios.org/
  *
@@ -72,7 +72,7 @@ typedef int pantheios_extras_atexit_atomic_int_t;
 # include <stdatomic.h>
 typedef atomic_int pantheios_extras_atexit_atomic_int_t;
 # define PANTHEIOS_EXTRAS_ATEXIT_ATOMIC_INC_(p)    (atomic_fetch_add((p), 1) + 1)
-# define PANTHEIOS_EXTRAS_ATEXIT_ATOMIC_DEC_(p)    (atomic_fetch_sub((p), 1) - 1)
+# define PANTHEIOS_EXTRAS_ATEXIT_ATOMIC_DEC_(p)    ((void)atomic_fetch_sub((p), 1))
 #elif defined(__GNUC__) || defined(__clang__)
 typedef int pantheios_extras_atexit_atomic_int_t;
 # define PANTHEIOS_EXTRAS_ATEXIT_ATOMIC_INC_(p)    __sync_add_and_fetch((p), 1)
@@ -248,3 +248,4 @@ pantheios_extras_atexit_log_string_(
 }
 
 /* ///////////////////////////// end of file //////////////////////////// */
+
diff --git a/test/scratch/test.scratch.atexit/CMakeLists.txt b/test/scratch/test.scratch.atexit/CMakeLists.txt
index 91d1d67..67169b4 100644
--- a/test/scratch/test.scratch.atexit/CMakeLists.txt
+++ b/test/scratch/test.scratch.atexit/CMakeLists.txt
@@ -1 +1 @@
-define_example_program(test.scratch.atexit test.scratch.atexit.c)
+define_example_program(test.scratch.atexit main.c)
diff --git a/test/scratch/test.scratch.atexit/test.scratch.atexit.c b/test/scratch/test.scratch.atexit/main.c
similarity index 78%
rename from test/scratch/test.scratch.atexit/test.scratch.atexit.c
rename to test/scratch/test.scratch.atexit/main.c
index 92db08f..e81da3b 100644
--- a/test/scratch/test.scratch.atexit/test.scratch.atexit.c
+++ b/test/scratch/test.scratch.atexit/main.c
@@ -1,10 +1,10 @@
 /* /////////////////////////////////////////////////////////////////////////
- * File:    test.scratch.atexit.c
+ * File:    main.c
  *
  * Purpose: Scratch test for Pantheios.Extras.AtExit.
  *
  * Created: 30th December 2011
- * Updated: 16th August 2026
+ * Updated: 21st August 2026
  *
  * ////////////////////////////////////////////////////////////////////// */
 
@@ -30,10 +30,18 @@ main(void)
 
     if (0 != r)
     {
+#ifdef _MSC_VER
+        char error_message[256];
+
+        strerror_s(error_message, sizeof(error_message), r);
+#else
+        char const* error_message = strerror(r);
+#endif
+
         fprintf(
             stderr
         ,   "failed to initialise Pantheios.Extras.AtExit : %s (%d)\n"
-        ,   strerror(r)
+        ,   error_message
         ,   r
         );
 
diff --git a/test/unit/test.unit.atexit.api/test.unit.atexit.api.c b/test/unit/test.unit.atexit.api/test.unit.atexit.api.c
index 2c8b6f6..e844c5a 100644
--- a/test/unit/test.unit.atexit.api/test.unit.atexit.api.c
+++ b/test/unit/test.unit.atexit.api/test.unit.atexit.api.c
@@ -100,7 +100,7 @@ test_init_after_uninit_fails(void)
 
 
 int
-main(int argc, char** argv)
+main(int argc, char* argv[])
 {
     int retCode = EXIT_SUCCESS;
     int verbosity = 2;
@@ -128,3 +128,4 @@ main(int argc, char** argv)
 
 
 /* ///////////////////////////// end of file //////////////////////////// */
+