gh-119102: Fix REPL for dumb terminal (GH-119332)

vstinner · miss-islington · commit bb5c0375538d · 2024-05-21T20:33:59.000Z
The site module gets the __main__ module to get _pyrepl.__main__. (cherry picked from commit de8f530) Co-authored-by: Victor Stinner <vstinner@python.org>
diff --git a/Lib/site.py b/Lib/site.py
@@ -523,7 +523,12 @@ def register_readline():
             pass
 
         def write_history():
-            from _pyrepl.__main__ import CAN_USE_PYREPL
+            try:
+                # _pyrepl.__main__ is executed as the __main__ module
+                from __main__ import CAN_USE_PYREPL
+            except ImportError:
+                CAN_USE_PYREPL = False
+
             try:
                 if os.getenv("PYTHON_BASIC_REPL") or not CAN_USE_PYREPL:
                     readline.write_history_file(history)
