Checkout when project is a submodule

Feedback & Bug Reports
1

I can’t run circleci from a git repository if this repository is a submodule.

To reproduce:

$> mkdir child && cd child && mkdir -p .circleci
$> cat<<EOF > .circleci/config.yml
version: 2
jobs:
  build:
    docker:
      - image: circleci/python:3.6.6-stretch
    steps:
      - checkout
EOF
$> git init && git add . && git commit -m 'Initial commit'
$> circleci local execute --job build  # it works!

$> cd ..
$> mkdir -p parent && cd parent
$> git init
$> git submodule add ../child child
$> cd child
$> circleci local execute --job build # it fails
[...]
====>> Checkout code
  #!/bin/bash -eo pipefail
mkdir -p /home/circleci/project && cd /tmp/_circleci_local_build_repo && git ls-files | tar -T - -c | tar -x -C /home/circleci/project && cp -a /tmp/_circleci_local_build_repo/.git /home/circleci/project
fatal: Not a git repository: ../.git/modules/child
Error: Exited with code 128
Step failed
Error: runner failed (exited with 101)
Task failed
Error: task failed

Any idea how to fix the problem?

Thanks,