From 6b4ad0fd74e3b24afea3ea025501b0fb2b0431d4 Mon Sep 17 00:00:00 2001
From: Nilesh M Negi <Nilesh.Negi@amd.com>
Date: Thu, 10 Jul 2025 17:19:53 -0500
Subject: [PATCH] [BUILD] Use fmt-header instead of libfmt (#1791)

---
 CMakeLists.txt                        | 2 +-
 cmake/Dependencies.cmake              | 3 ++-
 src/include/proxy_trace/proxy_trace.h | 3 +++
 src/misc/proxy_trace/proxy_trace.cc   | 3 +--
 test/CMakeLists.txt                   | 2 +-
 5 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 09481ca04e..83a119a069 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1091,7 +1091,7 @@ target_link_libraries(rccl INTERFACE hip::host)
 target_link_libraries(rccl PRIVATE   hip::device)
 target_link_libraries(rccl PRIVATE   dl)
 target_link_libraries(rccl PRIVATE   ${ROCM_SMI_LIBRARIES})
-target_link_libraries(rccl PRIVATE fmt::fmt)
+target_link_libraries(rccl PRIVATE fmt::fmt-header-only)
 if(ENABLE_MSCCLPP)
   target_link_libraries(rccl PRIVATE mscclpp_nccl)
 endif()
diff --git a/cmake/Dependencies.cmake b/cmake/Dependencies.cmake
index e4ed216182..fc084ecc03 100644
--- a/cmake/Dependencies.cmake
+++ b/cmake/Dependencies.cmake
@@ -119,6 +119,7 @@ set(CMAKE_INSTALL_LIBDIR lib CACHE STRING "Define install directory for librarie
 # Find or download/install fmt
 find_package(fmt QUIET)
 if(NOT fmt_FOUND)
+    set(FMT_INSTALL OFF)
     message(STATUS "fmt not found, fetching from source...")
     FetchContent_Declare(
         fmt
@@ -128,7 +129,7 @@ if(NOT fmt_FOUND)
     FetchContent_MakeAvailable(fmt)
 else()
     message(STATUS "Using system fmt")
-    get_target_property(FMT_INCLUDE_DIRS fmt::fmt INTERFACE_INCLUDE_DIRECTORIES)
+    get_target_property(FMT_INCLUDE_DIRS fmt::fmt-header-only INTERFACE_INCLUDE_DIRECTORIES)
     message(STATUS "fmt include directories: ${FMT_INCLUDE_DIRS}")
 endif()
 
diff --git a/src/include/proxy_trace/proxy_trace.h b/src/include/proxy_trace/proxy_trace.h
index bb8920eb60..0a1bfd8bd4 100644
--- a/src/include/proxy_trace/proxy_trace.h
+++ b/src/include/proxy_trace/proxy_trace.h
@@ -10,6 +10,9 @@
 #include <chrono>
 #include <cstdint>
 #include <deque>
+#ifndef FMT_HEADER_ONLY
+#define FMT_HEADER_ONLY 1
+#endif
 #include <fmt/format.h>
 #include <memory>
 #include <unordered_map>
diff --git a/src/misc/proxy_trace/proxy_trace.cc b/src/misc/proxy_trace/proxy_trace.cc
index b007d20ce3..5d585389d4 100644
--- a/src/misc/proxy_trace/proxy_trace.cc
+++ b/src/misc/proxy_trace/proxy_trace.cc
@@ -9,7 +9,6 @@
 #include "debug.h"
 #include "device.h"
 #include "proxy.h"
-#include <fmt/format.h>
 #include <map>
 
 constexpr int32_t kFinishedProxyOpItems = 32;
@@ -261,4 +260,4 @@ void facebook_rccl::addNewProxyOp(std::unique_ptr<ProxyTrace> &proxyTraceObj,
     proxyTraceObj->addNewProxyTraceOpImpl(key, extraInfo, opType, channelId,
                                           nSteps, nbytes, peerRank);
   }
-}
\ No newline at end of file
+}
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 277d07d4fa..31b14baf68 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -97,7 +97,7 @@ if(BUILD_TESTS)
   target_link_libraries(rccl-UnitTests PRIVATE hip::host hip::device hsa-runtime64::hsa-runtime64)
   target_link_libraries(rccl-UnitTests PRIVATE Threads::Threads)
   target_link_libraries(rccl-UnitTests PRIVATE dl)
-  target_link_libraries(rccl-UnitTests PRIVATE fmt::fmt)
+  target_link_libraries(rccl-UnitTests PRIVATE fmt::fmt-header-only)
   if(OPENMP_TESTS_ENABLED)
     target_link_libraries(rccl-UnitTests PRIVATE "${OpenMP_CXX_FLAGS}")
   endif()