use set -e to simplify exit codes in docker build

conda_smithy/templates/run_docker_build.tmpl

@@ -5,6 +5,8 @@
 # changes to this script, consider a proposal to conda-smithy so that other feedstocks can also
 # benefit from the improvement.
 
+set -e
+
 FEEDSTOCK_ROOT=$(cd "$(dirname "$0")/.."; pwd;)
 RECIPE_ROOT=$FEEDSTOCK_ROOT/{{ recipe_dir }}
 
@@ -33,6 +35,7 @@ rm -f "$DONE_CANARY"
 
 cat << EOF > "$FEEDSTOCK_ROOT/ci_support/build.sh"
 
+set -e
 export PYTHONUNBUFFERED=1
 
 echo "$config" > ~/.condarc
@@ -44,7 +47,7 @@ conda install --yes --quiet conda-forge-build-setup
 {{ build_setup }}{% endif -%}
 
 {%- block build %}
-conda build /recipe_root --quiet || exit 1
+conda build /recipe_root --quiet
 {%- endblock -%}
 
 # signal build-done with a file to protect against
@@ -63,20 +66,20 @@ CONTAINER=$(docker create -t \
            {{ docker.command }} /feedstock_root/ci_support/build.sh || exit $?)
 
 # build
-docker start -i $CONTAINER || exit 1
-test -f "$DONE_CANARY" || exit 1
+docker start -i $CONTAINER
+test -f "$DONE_CANARY"
 rm -f "$DONE_CANARY"
 
 # commit, so we can run upload in the same environment
-IMAGE=$(docker commit $CONTAINER || exit 1)
+IMAGE=$(docker commit $CONTAINER)
 
 # upload with the token passed through stdin
 # FIXME: Should this run if there is no token?
 cat << EOF | docker run --rm -i \
     $VOLUMES \
     $IMAGE \
     {{ docker.command }} || exit $?
-
+set -e
 export BINSTAR_TOKEN=${BINSTAR_TOKEN}
 
 {%- block test_and_upload %}
@@ -89,7 +92,7 @@ export BINSTAR_TOKEN=${BINSTAR_TOKEN}
 touch /feedstock_root/build_artefacts/conda-forge-build-done
 EOF
 
-test -f "$DONE_CANARY" || exit 1
+test -f "$DONE_CANARY"
 # everything succeeded, remove our container and image
 docker rm -f "$CONTAINER"
 docker rmi "$IMAGE"