Product alerts cron warnings

Question

Very recently I had to perform a minor upgrade on an extension (eBizmarts Mailchimp) in my Magento 2.1.7 installation. It went smoothly, as usual, even though it is terrifying to do this for fear of Magento completely breaking!

Anyway, after going through all the usual steps, and cleaning caches, etc, the site was returned to LIVE status, and all appeared to be normal. My steps are as follows: bin/magento setup:upgrade bin/magento setup:di:compile bin/magento setup:static-content:deploy en_GB bin/magento indexer:reindex bin/magento cache:clean bin/magento cache:flush Reapply permissions

That night, and every night since, I get an email at 1:20am with these contents:

Product alerts cron warnings

Warning: getimagesize(): Filename cannot be empty in /var/www/vhosts/website/htdocs/vendor/magento/module-catalog/Model/Product/Image.php on line 922

Warning: getimagesize(): Filename cannot be empty in /var/www/vhosts/website/htdocs/vendor/magento/module-catalog/Model/Product/Image.php on line 922

Warning: getimagesize(): Filename cannot be empty in /var/www/vhosts/website/htdocs/vendor/magento/module-catalog/Model/Product/Image.php on line 922

And so it continues, exactly the same for another 91 lines.

I do not see any corresponding error in any log files.

I can only imagine that something is perhaps cached on the server somewhere (in Magento) causing this, but it isn't actually causing an error? Maybe it is but I don't know about it.

Has anyone come across this before and knows what the issue is, and more importantly, how to fix it?

I am able to manually run cron on the server without any errors. When I use the command:

bin/magento cron:run

I get the following message back:

Ran jobs by schedule.

The error did not happen before the last update as mentioned above, and any products that have been added since the update have all got perfectly working images against them.

Could it be an unseen rogue image on a new item maybe? Or maybe 94 new items (one for each entry in this email)?

How do I debug this with no apparently useful info beyond this email?

Answer 1

I don't have a 2.1.7 available at the moment, but:

1. You could temporarily edit the core to output a more precise error message, maybe with a SKU
2. if you only do bin/magento cron:run when the conjob in question (product alerts) is not scheduled, it will not be executed and you won't be able to see the error messages. n98-magerun2 has a nice command sys:cron:run that actually lets you run a job by code. If you run php n98-magerun2.phar sys:cron:run catalog_product_alert from your command line, you could also be able to reproduce the error on your development machine
3. In my Magento (v2.1.8), there's a comment in line 922, but some placeholder-functionality using getimagesize() is right below. So you might want to check this setting first, to see if it is configured correctly