- Comment out socket (SO_REUSEPORT) and posix (O_SHLOCK, O_EXLOCK) constants

exposed on the API which are not implemented on GNU/Hurd. They would not
  work at runtime anyway.

Misc/NEWS

@@ -50,6 +50,10 @@ Core and Builtins
 Library
 -------
 
+- Comment out socket (SO_REUSEPORT) and posix (O_SHLOCK, O_EXLOCK) constants
+  exposed on the API which are not implemented on GNU/Hurd. They would not
+  work at runtime anyway.
+
 - Issue #25455: Fixed crashes in repr of recursive ElementTree.Element and
   functools.partial objects.
 

Modules/posixmodule.c

@@ -12658,12 +12658,14 @@ all_ins(PyObject *m)
 #ifdef O_LARGEFILE
     if (PyModule_AddIntMacro(m, O_LARGEFILE)) return -1;
 #endif
+#ifndef __GNU__
 #ifdef O_SHLOCK
     if (PyModule_AddIntMacro(m, O_SHLOCK)) return -1;
 #endif
 #ifdef O_EXLOCK
     if (PyModule_AddIntMacro(m, O_EXLOCK)) return -1;
 #endif
+#endif
 #ifdef O_EXEC
     if (PyModule_AddIntMacro(m, O_EXEC)) return -1;
 #endif

Modules/socketmodule.c

@@ -6529,9 +6529,11 @@ PyInit__socket(void)
 #ifdef  SO_OOBINLINE
     PyModule_AddIntMacro(m, SO_OOBINLINE);
 #endif
+#ifndef __GNU__
 #ifdef  SO_REUSEPORT
     PyModule_AddIntMacro(m, SO_REUSEPORT);
 #endif
+#endif
 #ifdef  SO_SNDBUF
     PyModule_AddIntMacro(m, SO_SNDBUF);
 #endif