Docs & test

Author: StanFromIreland

Doc/using/configure.rst

@@ -255,6 +255,27 @@ General Options
 
    .. versionadded:: 3.11
 
+.. option:: --with-missing-stdlib-config=FILE
+
+   Path to a `JSON <https://www.json.org/json-en.html>`_ configuration file
+   containing custom error messages for missing :term:`standard library` modules.
+
+   This option is intended for Python distributors who wish to provide
+   distribution-specific guidance when users encounter missing standard library
+   modules that are packaged separately.
+
+   The JSON file should map missing module names to custom error message strings.
+   For example, a configuration for the :mod:`tkinter` module:
+
+   .. code-block::json
+
+      {
+          "tkinter": "Install the python-tk package to use tkinter",
+          "_tkinter": "Install the python-tk package to use tkinter"
+      }
+
+   .. versionadded:: next
+
 .. option:: --enable-pystats
 
    Turn on internal Python performance statistics gathering.

Doc/whatsnew/3.15.rst

@@ -229,6 +229,12 @@ Improved error messages
      AttributeError: 'Container' object has no attribute 'area'. Did you mean: 'inner.area'?
 
 
+* The new configure option :option:`--with-missing-stdlib-config=FILE` allows
+  distributors to pass a `JSON <https://www.json.org/json-en.html>`_
+  configuration file containing custom error messages for missing
+  :term:`standard library` modules.
+
+
 Other language changes
 ======================
 

Lib/test/test_traceback.py

@@ -5051,7 +5051,7 @@ def test_no_site_package_flavour(self):
              b"or to enable your virtual environment?"), stderr
         )
 
-    def test_missing_stdlib_package(self):
+    def test_missing_stdlib_module(self):
         code = """
             import sys
             sys.stdlib_module_names |= {'spam'}
@@ -5061,6 +5061,17 @@ def test_missing_stdlib_package(self):
 
         self.assertIn(b"Standard library module 'spam' was not found", stderr)
 
+        code = """
+            import sys
+            import traceback
+            traceback.MISSING_STDLIB_MODULE_MESSAGES = {'spam': 'Install 'spam4life' for 'spam''}
+            sys.stdlib_module_names |= {'spam'}
+            import spam
+        """
+        _, _, stderr = assert_python_failure('-S', '-c', code)
+
+        self.assertIn(b"Install 'spam4life' for 'spam'", stderr)
+
 
 class TestColorizedTraceback(unittest.TestCase):
     maxDiff = None