From e12ef7bf2e525d117ff8bcf0d929cdab47f6e914 Mon Sep 17 00:00:00 2001
From: HanChao <chao1.han@intel.com>
Date: Fri, 9 Oct 2026 07:12:41 +0000
Subject: [PATCH 1/2] [xccl] WA: preload libccl.so.1 so the oneCCL legacy
 plugin can load

libccl.so.2 dlopen()s its legacy plugin libccl_legacy.so, which lists
libccl.so.1 in DT_NEEDED but ships without RPATH/RUNPATH. A dlopen'd object
does not inherit the search path of whoever pulled it in, so in a flat
PyPI/venv layout libccl.so.1 is looked up only in /etc/ld.so.cache, /lib and
/usr/lib. It is not found there and oneCCL fails with "oneCCL could not be
initialized! Could not load any plugin.", taking down every XCCL process
group creation unless the user sets LD_LIBRARY_PATH by hand.

dlopen("libccl.so.1", RTLD_NOW | RTLD_GLOBAL) from this library resolves it
through our own RPATH -- the same one that already locates libccl.so.2 -- and
leaves it in the global scope, so the plugin binds against the already-loaded
object instead of searching the filesystem.

Reproduced outside torch with a stub mirroring the real layout (NEEDED
libccl.so.2 + RUNPATH to the oneCCL dir, oneCCL not on LD_LIBRARY_PATH):

  without preload: dlopen libccl_legacy.so -> libccl.so.1: cannot open
                                              shared object file
  with preload   : dlopen libccl.so.1      -> OK
                   dlopen libccl_legacy.so -> OK
---
 cmake/XCCL.cmake  |  4 +++-
 src/xccl/xccl.cpp | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/cmake/XCCL.cmake b/cmake/XCCL.cmake
index 2fe9efd1b40..15a2c59fea9 100644
--- a/cmake/XCCL.cmake
+++ b/cmake/XCCL.cmake
@@ -24,7 +24,9 @@ if(NOT __XCCL_INCLUDED)
     ${XCCL_INCLUDE_DIR})
   # Wrap with --no-as-needed,...,--as-needed so it remains in NEEDED.
   # Once the weak attribute is removed upstream, this wrapper can be dropped.
+  # CMAKE_DL_LIBS is for the libccl.so.1 preload in src/xccl/xccl.cpp; it can go
+  # away together with that workaround.
   set_property(
     TARGET torch::xccl PROPERTY INTERFACE_LINK_LIBRARIES
-    "-Wl,--no-as-needed,${XCCL_LIBRARY},--as-needed")
+    "-Wl,--no-as-needed,${XCCL_LIBRARY},--as-needed" ${CMAKE_DL_LIBS})
 endif()
diff --git a/src/xccl/xccl.cpp b/src/xccl/xccl.cpp
index 8e08741934f..3cab633fb39 100644
--- a/src/xccl/xccl.cpp
+++ b/src/xccl/xccl.cpp
@@ -10,6 +10,38 @@
 
 #include <xccl/xccl.h>
 
+#ifndef _WIN32
+#include <dlfcn.h>
+#endif
+
+namespace {
+
+// WA. revert it once DLE 2026.2 releases.
+//
+// libccl.so.2 dlopen()s its legacy plugin libccl_legacy.so, which lists
+// libccl.so.1 in DT_NEEDED but ships without RPATH/RUNPATH. A dlopen'd object
+// does not inherit the search path of whoever pulled it in, so in the flat
+// PyPI/venv layout libccl.so.1 is looked up only in /etc/ld.so.cache, /lib and
+// /usr/lib; it is not found and oneCCL fails with "Could not load any plugin",
+// taking down every process group creation. Loading it here resolves it
+// through this library's RPATH -- the same one that already locates
+// libccl.so.2 -- and leaves it in the global scope for the plugin to bind
+// against.
+//
+// A failure here is expected on a full oneAPI/DLE layout, where the plugin
+// resolves its own dependencies, so it is deliberately not reported.
+//
+// oneCCL 2022.2 adds $ORIGIN search paths to its wheels; drop this once that
+// is the minimum supported version.
+[[maybe_unused]] const bool preloaded_oneccl_legacy_dep = []() {
+#ifndef _WIN32
+  (void)dlopen("libccl.so.1", RTLD_NOW | RTLD_GLOBAL);
+#endif
+  return true;
+}();
+
+} // namespace
+
 namespace c10d {
 namespace xccl {
 

From 7d3e518b6436f2f6c04f90d882b2e314364f60e6 Mon Sep 17 00:00:00 2001
From: HanChao <chao1.han@intel.com>
Date: Sat, 10 Oct 2026 00:53:04 +0000
Subject: [PATCH 2/2] also remove ci wa

---
 .github/actions/linux-uttest/action.yml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/.github/actions/linux-uttest/action.yml b/.github/actions/linux-uttest/action.yml
index 96b0acd4efc..b8b1b7879d6 100644
--- a/.github/actions/linux-uttest/action.yml
+++ b/.github/actions/linux-uttest/action.yml
@@ -171,7 +171,6 @@ runs:
       run: |
         xpu-smi topology -m
         mkdir -p ut_log/xpu_distributed
-        export PATH="${VENV_ROOT}/bin/libfabric:${PATH}"
         XCCL_ENABLE=$(python -c "import torch;print(torch.distributed.is_xccl_available())")
         if [[ "${XCCL_ENABLE,,}" == 'false' ]] || [[ "${XCCL_ENABLE}" == '0' ]]; then
           echo -e "[ERROR] XCCL is not enabled"