Problem changing to Production mode - Command returned non-zero exit code

Question

My Magento 2 was running normally, then I tried to change for production mode and I'm getting the following error:

Command returned non-zero exit code: 
`php -f /var/www/magento2.strip-curtains.com/public_html/bin/magento setup:di:compile-multi-tenant 2>&1`

When I run the command #php -f /var/www/magento2.strip-curtains.com/public_html/bin/magento setup:di:compile-multi-tenant 2>&1

[ReflectionException] Class \Smartwave\Megamenu\Model\Attribute\SubcatColumns does not exist
setup:di:compile-multi-tenant [--serializer="..."] [--extra-classes-file="..."] [--generation="..."] [--di="..."] [--exclude-pattern="..."] [--magento-init-params="..."]

I can only run the site if I set back to developer mode.

Answer 1

In this case I think you are running into one of three issues.

1. You need to run php bin/magento setup:upgrade to update the list of modules in case you have removed or changed one. If you did remove the Smartwave module without resetting your app/etc/config.php it's possible to get this error.

2. You have removed the Smartwave module but there is still code the uses some of it's classes or extends from it that haven't been updated.

3. You need to clear that var folder's that could have old content in them. They are typically var/di, var/view_preprocessed, var/cache, var/page_cache, var/generation. Clearing these might solve the issue.

From here, I would grep for the use of the Smartwave module in the app and vendor folders and see what comes up to figure out where it's being used.

grep -r "Smartwave" app/*