use a script instead of piping to stdin in run_docker_build

conda_smithy/feedstock_content/.gitignore

@@ -1,3 +1,4 @@
 *.pyc
 
 build_artifacts
+.circleci/build.sh

conda_smithy/templates/run_docker_build.tmpl

@@ -5,6 +5,7 @@
 # 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 }}
 
@@ -25,6 +26,7 @@ show_channel_urls: true
 CONDARC
 )
 
+
 # In order for the conda-build process in the container to write to the mounted
 # volumes, we need to run with the same id as the host machine, which is
 # normally the owner of the mounted volumes, or at least has write permission
@@ -37,19 +39,15 @@ fi
 
 rm -f "$FEEDSTOCK_ROOT/build_artifacts/conda-forge-build-done"
 
-cat << EOF | {{ docker.executable }} run -i \
-                        -v "${RECIPE_ROOT}":/home/conda/recipe_root \
-                        -v "${FEEDSTOCK_ROOT}":/home/conda/feedstock_root \
-                        -e CONFIG="$CONFIG" \
-                        -e HOST_USER_ID="${HOST_USER_ID}" \
-                        -a stdin -a stdout -a stderr \
-                        {{ docker.image }} \
-                        {{ docker.command }} || exit 1
+ARTIFACTS="$FEEDSTOCK_ROOT/build_artifacts"
+
+test -d "$ARTIFACTS" || mkdir "$ARTIFACTS"
+DONE_CANARY="$ARTIFACTS/conda-forge-build-done"
+rm -f "$DONE_CANARY"
+
+cat << EOF > "$FEEDSTOCK_ROOT/.circleci/build.sh"
 
 set -e
-set +x
-export BINSTAR_TOKEN=${BINSTAR_TOKEN}
-set -x
 export PYTHONUNBUFFERED=1
 
 echo "$config" > ~/.condarc
@@ -60,17 +58,33 @@ conda install --yes --quiet conda-forge-ci-setup=1
 {% if build_setup -%}
 {{ build_setup }}{% endif -%}
 
-conda build /home/conda/recipe_root -m /home/conda/feedstock_root/.ci_support/${CONFIG}.yaml --quiet || exit 1
+conda build /home/conda/recipe_root -m /home/conda/feedstock_root/.ci_support/${CONFIG}.yaml --quiet
 {%- for owner, channel in channels['targets'] %}
-{{ upload_script }} /home/conda/recipe_root {{ owner }} --channel={{ channel }} -m /home/conda/feedstock_root/.ci_support/${CONFIG}.yaml || exit 1
+{{ upload_script }} /home/conda/recipe_root {{ owner }} --channel={{ channel }} -m /home/conda/feedstock_root/.ci_support/${CONFIG}.yaml
 {%- endfor %}
 
 touch /home/conda/feedstock_root/build_artifacts/conda-forge-build-done
 EOF
 
-# double-check that the build got to the end
-# see https://github.com/conda-forge/conda-smithy/pull/337
-# for a possible fix
+set +x
+echo "BINSTAR_TOKEN=${BINSTAR_TOKEN}" > "${FEEDSTOCK_ROOT}/env"
 set -x
-test -f "$FEEDSTOCK_ROOT/build_artifacts/conda-forge-build-done" || exit 1
 
+# Create and run the container in two commands,
+# so the token env isn't on disk too long
+
+CONTAINER=$(docker create -t \
+           -v "${RECIPE_ROOT}":/home/conda/recipe_root \
+           -v "${FEEDSTOCK_ROOT}":/home/conda/feedstock_root \
+           --env-file ${FEEDSTOCK_ROOT}/env \
+           -e HOST_USER_ID="${HOST_USER_ID}" \
+           {{ docker.image }} \
+           {{ docker.command }} \
+           /home/conda/feedstock_root/.circleci/build.sh || exit $?)
+
+rm "${FEEDSTOCK_ROOT}/env"
+# do it
+docker start -i $CONTAINER
+
+# verify that the end of the script was reached
+test -f "$DONE_CANARY"