Intermittent PHP Abstract Class Error
I think you've run into this opcache bug. This isn't exactly the same situation but probably related.
After calling opcache_reset() function we encounter some weird errors. It happens randomly on servers (10 of 400 servers production)
Some letter a replaced by others, Class seems to be already declared.. etc
Example of errors triggered after opcache_reset():
- PHP Fatal error: Class XXX contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (YYY::funczzz) in /dir/dir/x.php on line 20
The ticket is closed because the developers don't have enough information to reproduce it. If you could come up with the smallest reproducible case I recommend reporting it. Create a very small Slim app and then use JMeter or another tool to make many requests. Post your findings.
Meanwhile the only workaround might be to turn off opcache in php.ini:
opcache.enable=0Of course this will drastically hurt performance. Until it's fixed you'll have to choose between performance or periodically restarting Apache.
If turning the cache off doesn't work then the only cause I could think of is an intermittent problem with the opcode compiler. Cached or not the compiled version must have an error in it. Opening a reproducible ticket with the PHP devs or debugging the PHP source yourself would be the only way forward if this is the cause.
If you develop on Windows, I would recommend that you DON'T use XAMPP or WAMPP, and try out a real development server using Linux on a VM.
Try installing Vagrant and Virtualbox, then head to puphpet.com, which can generate you a virtual machine configuration. Unzip the download, cd in to the folder, type vagrant up. Then just point your host at the VM. I'll bet once you have a real development environment that this error will go away. Your other option is Docker, but that has a bit of a learning curve.
The problem isn't your code (or your vendor code), but your platform.