text: #!/usr/bin/env bash
  
  set -o errexit
  set -o verbose
  set -o pipefail
  set -o nounset
  set -o errtrace
  
  __file=developer-scripts/travis/install.linux.sh
  
  # Error tracing
  # requires `set -o errtrace`
  __caf_err_report() {
      error_code=${?}
      echo "Error (code=${error_code}) in ${__file} in function ${1} on line ${2}." >&2
      false
      return ${error_code}
  }
  # Always provide an error backtrace
  trap '__caf_err_report "${FUNCNAME:-.}" ${LINENO}' ERR
  
  if [[ -n "${TRAVIS_TAG}" ]] && ${TRAVIS_SECURE_ENV_VARS} ; then
      brew update > /dev/null
      brew ls --versions gpg2 >/dev/null || brew install gpg2
      brew outdated gpg2 || brew upgrade gpg2
      type -P openssl || brew install openssl
      curl https://izaakbeekman.com/izaak.pubkey.txt | gpg --import
      git tag -v "${TRAVIS_TAG}"
  fi
  gfortran --version || true
  gcc --version || true
  g++ --version || true
  