gh-129098: avoid using content of _pyrepl/__main__.py when reporting tracebacks

[picnixz]

I don't know how to test this :)

• Issue: REPL shows source code from _pyrepl.__main__.py #129098

[picnixz]

I'm marking the PR as ready for review to know whether this is the correct alternative.

[skirpichev]

I don't know how to test this :)

Maybe something like this (that for unpatched version):

diff --git a/Lib/test/test_pyrepl/test_pyrepl.py b/Lib/test/test_pyrepl/test_pyrepl.py
index 3540d2a5a4..1d76121364 100644
--- a/Lib/test/test_pyrepl/test_pyrepl.py
+++ b/Lib/test/test_pyrepl/test_pyrepl.py
@@ -1216,6 +1216,15 @@ def test_python_basic_repl(self):
         self.assertNotIn("Exception", output)
         self.assertNotIn("Traceback", output)
 
+    @force_not_colorized
+    def test_no_pyrepl_source_in_exc(self):
+        env = os.environ.copy()
+        commands = "eval(compile('spam', 'spam', 'eval'))\nexit()\n"
+        env.pop("PYTHON_BASIC_REPL", None)
+        output, exit_code = self.run_repl(commands, env=env)
+        self.assertIn("Traceback", output)
+        self.assertIn("# Important: don't add things to this module", output)
+
     @force_not_colorized
     def test_bad_sys_excepthook_doesnt_crash_pyrepl(self):
         env = os.environ.copy()

[picnixz]

@pablogsal @ambv Could you have a look at this one to see if we can use this fix?