message: build: cleanup ci/.bazelrc.
  Using cp results in:
  cp: '/source/.bazelrc' and '/build/envoy-filter-example/.bazelrc' are the same file
  *Risk Level*: Low
  *Testing*: ./ci/run_envoy_docker.sh './ci/do_circle_ci.sh bazel.dev'
  *Docs Changes*: n/a
  *Release Notes*: n/a
  Broken in
diff: @@ -108,6 +108,19 @@ mkdir -p "${ENVOY_COVERAGE_DIR}"
  # This is where we build for bazel.release* and bazel.dev.
  export ENVOY_CI_DIR="${ENVOY_SRCDIR}"/ci
  +function cleanup() {
  + # Remove build artifacts. This doesn't mess with incremental builds as these
  + # are just symlinks.
  + rm -rf "${ENVOY_SRCDIR}"/bazel-*
  + rm -rf "${ENVOY_CI_DIR}"/bazel-*
  + rm -rf "${ENVOY_CI_DIR}"/bazel
  + rm -rf "${ENVOY_CI_DIR}"/tools
  + rm -f "${ENVOY_CI_DIR}"/.bazelrc
  +}
  +
  +cleanup
  +trap cleanup EXIT
  +
  # Hack due to https://github.com/envoyproxy/envoy/issues/838 and the need to have
  # .bazelrc available for build linkstamping.
  mkdir -p "${ENVOY_FILTER_EXAMPLE_SRCDIR}"/bazel
  @@ -123,13 +136,3 @@ ln -sf "${ENVOY_SRCDIR}"/tools/bazel.rc "${ENVOY_FILTER_EXAMPLE_SRCDIR}"/tools/
  ln -sf "${ENVOY_SRCDIR}"/tools/bazel.rc "${ENVOY_CI_DIR}"/tools/
  export BUILDIFIER_BIN="/usr/local/bin/buildifier"
  -
  -function cleanup() {
  - # Remove build artifacts. This doesn't mess with incremental builds as these
  - # are just symlinks.
  - rm -rf "${ENVOY_SRCDIR}"/bazel-*
  - rm -rf "${ENVOY_CI_DIR}"/bazel-*
  - rm -rf "${ENVOY_CI_DIR}"/bazel
  - rm -rf "${ENVOY_CI_DIR}"/tools
  -}
  -trap cleanup EXIT
  