def METHOD_NAME(create_command, first_app_config):
    "If ldd returns unexpected content, an error is raised"
    # Mock an app being built on docker
    create_command.target_image = "somevendor:surprising"
    first_app_config.target_image = "somevendor:surprising"
    # Mock a verified Docker, and unexpected ldd output
    create_command.tools.docker = MagicMock()
    create_command.tools.docker.check_output.return_value = (
        "I don't know what this is, but it isn't ldd output."
    )
    # An error is raised when getting the glibc version
    with pytest.raises(
        BriefcaseCommandError,
        match=r"Unable to parse glibc dependency version from version string.",
    ):
        create_command.target_glibc_version(first_app_config)
    # Docker was consulted for the glibc version
    create_command.tools.docker.check_output.assert_called_once_with(
        ["ldd", "--version"],
        image_tag="somevendor:surprising",
    )