Issue #15020: The program name used to search for Python's path is now "python3" under Unix, not "python".
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 5a96bae..4609468 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -696,7 +696,11 @@
     PyInterpreterState_Delete(interp);
 }
 
+#ifdef MS_WINDOWS
 static wchar_t *progname = L"python";
+#else
+static wchar_t *progname = L"python3";
+#endif
 
 void
 Py_SetProgramName(wchar_t *pn)