我试图pytest-qt在CircleCI上运行需要（用于测试PySide2对话框）的测试。我收到以下错误：

xdpyinfo was not found, X start can not be checked! Please install xdpyinfo!
============================= test session starts ==============================
platform linux -- Python 3.6.8, pytest-5.0.0, py-1.8.0, pluggy-0.12.0 -- /home/circleci/project-caveman/venv/bin/python3
cachedir: .pytest_cache
PySide2 5.13.0 -- Qt runtime 5.13.0 -- Qt compiled 5.13.0
rootdir: /home/circleci/project-caveman
plugins: cov-2.7.1, xvfb-1.2.0, qt-3.2.2
collected 1 item

tests/test_main.py::test_label_change_on_button_press Fatal Python error: Aborted

Aborted (core dumped)
Exited with code 134

我正在使用此配置文件：

version: 2
jobs:
  build:
    working_directory: ~/project-caveman
    docker:
      - image: circleci/python:3.6.8-stretch
    steps:
      - checkout

      # Dependencies
      - restore_cache:
          keys:
            - venv-{{ .Branch }}-{{ checksum "setup.py" }}
            - venv-{{ .Branch }}-
            - venv-
      - run:
          name: Install dependencies
          command: |
            python3 -m venv venv
            . venv/bin/activate
            pip install -e .[test] --progress-bar off
      - save_cache:
          key: venv-{{ .Branch }}-{{ checksum "setup.py" }}
          paths:
            - "venv"

      # Tests
      - run:
          name: Pytest
          command: |
            mkdir test-reports
            . venv/bin/activate
            xvfb-run -a pytest -s -v --doctest-modules --junitxml test-reports/junit.xml --cov=coveralls --cov-report term-missing
      - store_test_results:
          path: test-reports
      - run:
          name: Coveralls
          command: coveralls

非常感谢您的任何帮助。