CI failure at "Checkout code" step - fatal: Could not read from remote repository.

[Rob--W]

https://app.circleci.com/pipelines/github/mozilla/FirefoxColor/1087/workflows/8f5362d6-3b2b-498f-8fab-e4ba07ea3820/jobs/2787

Here is the end of the log:

Using SSH Config Dir '/home/circleci/.ssh'
git version 2.34.1
Cloning git repository
Cloning into '.'...
Warning: Permanently added the ECDSA host key for IP address '140.82.113.4' to the list of known hosts.
git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

exit status 128

CircleCI received exit code 128

For the record, CIRCLE_REPOSITORY_URL=git@github.com:mozilla/FirefoxColor.git and as part of the checkout the following logic is run:

export GIT_SSH_COMMAND='ssh -i "$SSH_CONFIG_DIR/id_rsa" -o UserKnownHostsFile="$SSH_CONFIG_DIR/known_hosts"'

# use git+ssh instead of https
git config --global url."ssh://git@github.com".insteadOf "https://github.com" || true
git config --global gc.auto 0 || true

if [ -e '/home/circleci/FirefoxColor/.git' ] ; then
  echo 'Fetching into existing repository'
  existing_repo='true'
  cd '/home/circleci/FirefoxColor'
  git remote set-url origin "$CIRCLE_REPOSITORY_URL" || true
else
  echo 'Cloning git repository'
  existing_repo='false'
  mkdir -p '/home/circleci/FirefoxColor'
  cd '/home/circleci/FirefoxColor'
  git clone --no-checkout "$CIRCLE_REPOSITORY_URL" .
fi

[diox]

Do you have a Deploy Key set up in CircleCI, and authorized with GitHub for this repo?