From a5120091700e20cfd59db9686721af11eca1e354 Mon Sep 17 00:00:00 2001
From: Pratik Mankawde <3397372+pratikmankawde@users.noreply.github.com>
Date: Sat, 11 Jul 2026 17:59:33 +0100
Subject: [PATCH] fix(telemetry): replace std::format with string concat for
 gcc-12

libstdc++ ships <format> starting with gcc-13, so std::format in
SpanGuard::span() fails to compile on gcc-12. Build the "<prefix>.<name>"
span name via std::string::append instead and drop the <format> include.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 src/libxrpl/telemetry/SpanGuard.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/libxrpl/telemetry/SpanGuard.cpp b/src/libxrpl/telemetry/SpanGuard.cpp
index 26c14c20be..2fc0760124 100644
--- a/src/libxrpl/telemetry/SpanGuard.cpp
+++ b/src/libxrpl/telemetry/SpanGuard.cpp
@@ -37,7 +37,6 @@
 
 #include <cstdint>
 #include <exception>
-#include <format>
 #include <memory>
 #include <string>
 #include <string_view>
@@ -177,7 +176,9 @@ SpanGuard::span(TraceCategory cat, std::string_view prefix, std::string_view nam
     auto* tel = Telemetry::getInstance();
     if ((tel == nullptr) || !tel->isEnabled() || !isCategoryEnabled(*tel, cat))
         return {};
-    auto fullName = std::format("{}.{}", prefix, name);
+    std::string fullName;
+    fullName.reserve(prefix.size() + 1 + name.size());
+    fullName.append(prefix).append(1, '.').append(name);
     return SpanGuard(std::make_unique<Impl>(tel->startSpan(fullName, categoryToSpanKind(cat))));
 }