https://bugs.gentoo.org/797649
https://github.com/Alexays/Waybar/pull/1144

From: John Helmert III <jchelmert3@posteo.net>
Date: Tue, 29 Jun 2021 21:29:12 -0500
Subject: [PATCH] libfmt >=8.0.0 compatibility
--- a/include/util/format.hpp
+++ b/include/util/format.hpp
@@ -35,7 +35,11 @@ namespace fmt {
             // The rationale for ignoring it is that the only reason to specify
             // an alignment and a with is to get a fixed width bar, and ">" is
             // sufficient in this implementation.
+#if FMT_VERSION < 80000
             width = parse_nonnegative_int(it, end, ctx);
+#else
+            width = detail::parse_nonnegative_int(it, end, -1);
+#endif
           }
           return it;
         }
--- a/src/modules/clock.cpp
+++ b/src/modules/clock.cpp
@@ -196,6 +196,9 @@ template <>
 struct fmt::formatter<waybar_time> : fmt::formatter<std::tm> {
   template <typename FormatContext>
   auto format(const waybar_time& t, FormatContext& ctx) {
+#if FMT_VERSION >= 80000
+	auto& tm_format = specs;
+#endif
     return format_to(ctx.out(), "{}", date::format(t.locale, fmt::to_string(tm_format), t.ztime));
   }
 };