PHP升级到7.2后，Laravel / mPDF非数字值遇到ErrorException

Question

我将php7.1更新为php7.2.1（PHP 7.2.1（cli））我的laravel pdf未生成显示以下错误：

(1/1) ErrorException

A non-numeric value encountered
in mpdf.php (line 30648)

at HandleExceptions->handleError(
    2, 
    'A non-numeric value encountered', 
    '/opt/lampp/htdocs/mysite/vendor/mpdf/mpdf/mpdf.php', 
    30648, 
    array(
        'size' => 0, 
        'maxsize' => 190.00155555555551245561218820512294769287109375, 
        'fontsize' => 3.704166666666667051543981870054267346858978271484375,
        'usefontsize' => false)
    )
in mpdf.php (line 30648)