PHP/Upgrading to PHP 7.1

Compatibility check
PHP 7 has some major changes from the previous 5.x versions. All scripts should be checked before upgrading.

PHP 7 Compatiblity Checker is a wonderful tool to do this automatically.

PHP Targets
To upgrade a system to PHP 7.1, first set the PHP_TARGETS variable in :

Installation
Install PHP 7.1:

Replace APC
To build with the  USE flag (the default) while allowing the use of APC userland functions such as , install APCu, which emulates APC but only has user caching functions. This may be necessary for older projects that rely on APC for caching.

Install APCu:

The PHP 7 versions of pecl-apcu have a new syntax which need changes to support. Fortunately, there is a compatibility package, :

Switch to PHP 7.1
Switch to it using for all SAPIs:

When other SAPIs are in use, be sure to run  for those as well.

Re-install compatible extensions
Since changing PHP_TARGETS is technically a USE flag change, it suffices to simply with flags checking for new USE flags and all extensions should re-build.

Migrate the configuration files
The different slots have different configuration paths. Please take care to migrate the configuration files before making use of a new slot.

Uninstall old PHP versions
For example, to remove PHP 5.6:

Restart PHP-FPM
Restart PHP-FPM if applicable: