Revert of [ci] remove old USER_LAND code from ci scripts

- pytorch#80045

Author: pruthvistony

.ci/pytorch/common.sh

@@ -19,6 +19,14 @@ if [[ "${BUILD_ENVIRONMENT}" == *rocm* ]]; then
   export HSA_FORCE_FINE_GRAIN_PCIE=1
 fi
 
+# This token is used by a parser on Jenkins logs for determining
+# if a failure is a legitimate problem, or a problem with the build
+# system; to find out more, grep for this string in ossci-job-dsl.
+echo "ENTERED_USER_LAND"
+
+trap_add cleanup EXIT
+
+
 # TODO: Renable libtorch testing for MacOS, see https://github.com/pytorch/pytorch/issues/62598
 # shellcheck disable=SC2034
 BUILD_TEST_LIBTORCH=0

.ci/pytorch/common_utils.sh

@@ -39,6 +39,19 @@ trap_add() {
 # inherit them unless the trace attribute is set
 declare -f -t trap_add
 
+# NB: define this function before set -x, so that we don't
+# pollute the log with a premature EXITED_USER_LAND ;)
+function cleanup {
+  # Note that if you've exited user land, then CI will conclude that
+  # any failure is the CI's fault.  So we MUST only output this
+  # string
+  retcode=$?
+  set +x
+  if [ $retcode -eq 0 ]; then
+    echo "EXITED_USER_LAND"
+  fi
+}
+
 function assert_git_not_dirty() {
     # TODO: we should add an option to `build_amd.py` that reverts the repo to
     #       an unmodified state.