Troubleshooting Magento 1.9.2.4 with PHP 7

Question

I've been doing some research and decided to go ahead with an upgrade to PHP v7. Initially my front-end and back-end were non responsive, just a blank white page.

Running the latest version of Magento 1.9.2.4.

I came across the inchoo compatibility module: http://inchoo.net/magento/its-alive/

This resolved my front-end issues, but I cannot login to my admin panel. The header loads but that is it. There are no errors in any of the logs.

I did a search in my local and community directories to check for incompatible code that might be responsible:

grep -rnPe .'->\$.+\[.+\]\(.*\)'

The only results were from the core which are resolved by the Inchoo PHP 7 module.

Others seem to have had the exact same problem:

from magento 1.9.2.2, uploaded Seven to the server, then change to PHP 7.0 and my side goes blank. No errors, just nothing on the screen.

I'm sure this is a common issue and would like to get this documented since I could not find any solution to resolve this.

With no errors in the logs I am at a loss on how to troubleshoot the back-end issues.

Can someone provide a solution or guide me into how to resolve this?

For the close happy people in this section of SE:

I'm not asking if it is compatible, I'm asking how to make it work given the troubleshooting I've already done

Answer 1

Since Magento 1.9 with the Inchoo patch and without additional extensions is compatible with PHP 7, it's a problem with either a third party extension or custom code and I can only give you hints where to look:

The header loads but that is it

This usually means, PHP has crashed with a Fatal Error during template rendering. With developer mode turned on you should see the error message if you use "View Source" in your browser. If not, check the PHP error logs (not Magento error logs!)

I did a search in my local and community directories to check for incompatible code that might be responsible:

 grep -rnPe .'->\$.+\[.+\]\(.*\)'

The regex you used addresses only one particular compatibility issue. To find more potential issues, there are static analysis tools like https://github.com/sstalle/php7cc - use them instead.