https://bugs.gentoo.org/963165
https://github.com/gerbera/gerbera/commit/f8e158bc72986e46b93d05358c29db0c10f2fe9f
--- a/src/web/config_load.cc
+++ b/src/web/config_load.cc
@@ -150,7 +150,11 @@ void Web::ConfigLoad::addNewValue(
 template <typename T>
 void Web::ConfigLoad::setValue(Json::Value& item, const T& value)
 {
+#if FMT_VERSION >= 120000
+    static_assert(fmt::is_formattable<T, fmt::format_context>::value, "T must be formattable");
+#else
     static_assert(fmt::has_formatter<T, fmt::format_context>::value, "T must be formattable");
+#endif
     item[CONFIG_LOAD_VALUE] = fmt::to_string(value);
 }