scope func var and change exit capture eval

Author: petetomasik

commands/run.sh

@@ -348,8 +348,9 @@ fi
 
 if [[ "${BUILDKITE_PLUGIN_DOCKER_ALWAYS_PULL:-false}" =~ ^(true|on|1)$ ]] ; then
   echo "--- :docker: Pulling ${image}"
-  if ! retry "${BUILDKITE_PLUGIN_DOCKER_PULL_RETRIES:-3}" \
-       docker pull "${image}" ; then
+  retry "${BUILDKITE_PLUGIN_DOCKER_PULL_RETRIES:-3}" docker pull "${image}"
+  retry_exit_status="$?"
+  if [ $retry_exit_status -ne 0 ] ; then
     echo "!!! :docker: Pull failed."
     exit "$retry_exit_status"
   fi

lib/shared.bash

@@ -8,7 +8,7 @@ function retry {
   local attempts=1
 
   until "$@"; do
-    retry_exit_status=$?
+    local retry_exit_status=$?
     echo "Exited with $retry_exit_status"
     if (( retries == "0" )); then
       return $retry_exit_status