From 07ac716c1ac5999964bd583806ec37e928251119 Mon Sep 17 00:00:00 2001
From: Sylvain Jeaugey <sjeaugey@nvidia.com>
Date: Thu, 18 Jun 2020 15:00:05 -0700
Subject: [PATCH] Fix #47 : compilation error on NCCL<2.7

Return an error when trying to run alltoall test when compiled
against NCCL<2.7.
---
 src/alltoall.cu | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/alltoall.cu b/src/alltoall.cu
index aea9370f65..31cfca090d 100644
--- a/src/alltoall.cu
+++ b/src/alltoall.cu
@@ -64,14 +64,18 @@ testResult_t AlltoAllRunColl(void* sendbuff, void* recvbuff, size_t count, ncclD
   size_t rankOffset = count * wordSize(type);
   if (count == 0) return testSuccess;
 
+#if NCCL_MAJOR < 2 || NCCL_MINOR < 7
+  printf("NCCL 2.7 or later is needed for alltoall. This test was compiled with %d.%d.\n", NCCL_MAJOR, NCCL_MINOR);
+  return testNcclError;
+#else
   NCCLCHECK(ncclGroupStart());
   for (int r=0; r<nRanks; r++) {
     NCCLCHECK(ncclSend(((char*)sendbuff)+r*rankOffset, count, type, r, comm, stream));
     NCCLCHECK(ncclRecv(((char*)recvbuff)+r*rankOffset, count, type, r, comm, stream));
   }
   NCCLCHECK(ncclGroupEnd());
-
   return testSuccess;
+#endif
 }
 
 struct testColl alltoAllTest = {