https://github.com/facebook/folly/commit/a65b35c03797c86969a7b0d9ec281935a21cfa18
https://github.com/facebook/folly/pull/2022

From a65b35c03797c86969a7b0d9ec281935a21cfa18 Mon Sep 17 00:00:00 2001
From: Giuseppe Ottaviano <ott@meta.com>
Date: Sun, 18 Jun 2023 00:40:43 -0700
Subject: [PATCH] fmt/core.h is enough in Core.cpp

Reviewed By: Orvid, luciang

Differential Revision: D46788525

fbshipit-source-id: 03da65f3499ca56b34baa4e75b2340bea36690f6
---
 folly/futures/detail/Core.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/folly/futures/detail/Core.cpp b/folly/futures/detail/Core.cpp
index 26bd4afbffe..858229100f9 100644
--- a/folly/futures/detail/Core.cpp
+++ b/folly/futures/detail/Core.cpp
@@ -18,7 +18,7 @@
 
 #include <new>
 
-#include <fmt/format.h>
+#include <fmt/core.h>
 #include <folly/lang/Assume.h>
 
 namespace folly {

From d783a64391c02b40d78dfc6be04932fa45c46b9a Mon Sep 17 00:00:00 2001
From: Marcus Holland-Moritz <github@mhxnet.de>
Date: Tue, 20 Jun 2023 11:59:42 +0200
Subject: [PATCH] Fix libfmt errors from not finding enum formatter

Recent versions of libfmt have become more strict and require
`enum` types to be formattable:

  static assertion failed due to requirement 'formattable': Cannot format an argument. To make type T formattable provide a formatter<T> specialization: https://fmt.dev/latest/api.html#udt

This is a quick fix to simply use the underlying type.
--- a/folly/futures/detail/Core.cpp
+++ b/folly/futures/detail/Core.cpp
@@ -19,6 +19,7 @@
 #include <new>
 
 #include <fmt/core.h>
+#include <folly/Utility.h>
 #include <folly/lang/Assume.h>
 
 namespace folly {
@@ -30,7 +31,7 @@ namespace {
 template <class Enum>
 void terminate_unexpected_state(fmt::string_view context, Enum state) {
   terminate_with<std::logic_error>(
-      fmt::format("{} unexpected state: {}", context, state));
+      fmt::format("{} unexpected state: {}", context, to_underlying(state)));
 }
 
 } // namespace