use pybind11::gil_scoped_acquire instead of PyGILState_*

include/pybind11/common.h

@@ -482,14 +482,7 @@ public:
         : std::runtime_error(e.what()), type(e.type), value(e.value),
           trace(e.trace) { e.type = e.value = e.trace = nullptr; }
 
-    ~error_already_set() {
-        if (value) {
-            PyGILState_STATE state = PyGILState_Ensure();
-            PyErr_Restore(type, value, trace);
-            PyErr_Clear();
-            PyGILState_Release(state);
-        }
-    }
+    inline ~error_already_set(); // implementation in pybind11.h
 
     error_already_set& operator=(const error_already_set &) = delete;
 

include/pybind11/pybind11.h

@@ -1647,6 +1647,14 @@ class gil_scoped_acquire { };
 class gil_scoped_release { };
 #endif
 
+error_already_set::~error_already_set() {
+    if (value) {
+        gil_scoped_acquire gil;
+        PyErr_Restore(type, value, trace);
+        PyErr_Clear();
+    }
+}
+
 inline function get_type_overload(const void *this_ptr, const detail::type_info *this_type, const char *name)  {
     handle py_object = detail::get_object_handle(this_ptr, this_type);
     if (!py_object)