Expect the Distributed test suite to fail on 1.6 and 1.7 when multithreading is enabled

Author: DilumAluthge

.buildkite/pipelines/main/platforms/tester_linux.yml

@@ -58,17 +58,33 @@ steps:
       export OPENBLAS_NUM_THREADS=8
 
       if [[ "$${BUILDKITE_STEP_KEY:?}"   == "tester_linux64_rr" ]]; then
+
         # For the `rr` job, we disable multi-threading.
         export JULIA_NUM_THREADS=1
         $${JULIA_UNDER_RR:?} -e 'Base.runtests(["all"]; ncores = parse(Int, ENV["JULIA_RRCAPTURE_NUM_CORES"]))'
+
       elif [[ "$${BUILDKITE_STEP_KEY:?}" == "tester_linux64_st" ]]; then
+
         # "_st" = single-threaded
         export JULIA_NUM_THREADS=1
         $${JULIA_BINARY:?} -e 'Base.runtests(["all"]; ncores = Sys.CPU_THREADS)'
+
       elif [[ "$${BUILDKITE_STEP_KEY:?}" == "tester_linux64_mt" ]]; then
+
         # "_mt" = multi-threaded
         export JULIA_NUM_THREADS=16
-        $${JULIA_BINARY:?} -e 'Base.runtests(["all"]; ncores = Sys.CPU_THREADS)'
+        if [[ "$${BUILDKITE_PIPELINE_SLUG:?}"   == "julia-release-1-dot-6" ]]; then
+          # On Julia 1.6, the Distributed test suite is expected to fail when multithreading is enabled.
+          $${JULIA_BINARY:?} -e 'Base.runtests(["all", "--skip", "Distributed"]; ncores = Sys.CPU_THREADS)'
+        elif [[ "$${BUILDKITE_PIPELINE_SLUG:?}" == "julia-release-1-dot-7" ]]; then
+          # On Julia 1.7, the Distributed test suite is expected to fail when multithreading is enabled.
+          $${JULIA_BINARY:?} -e 'Base.runtests(["all", "--skip", "Distributed"]; ncores = Sys.CPU_THREADS)'
+        else
+          $${JULIA_BINARY:?} -e 'Base.runtests(["all"]; ncores = Sys.CPU_THREADS)'
+        fi
+
       else
+
         $${JULIA_BINARY:?} -e 'Base.runtests(["all"]; ncores = Sys.CPU_THREADS)'
+
       fi