def METHOD_NAME(
    tmpdir, mock_packages, mock_archive, mock_fetch, config, install_mockery
):
    install("extendee")
    install("extension1@1.0")
    install("extension1@2.0")
    viewpath = str(tmpdir.mkdir("view"))
    view("symlink", viewpath, "extension1@1.0")
    output = view("symlink", viewpath, "extension1@2.0")
    assert "Package conflict detected" in output