Here are some of the PHP 7.4 compatibility issues the community spotted so far:
- PerchUtil::safe_stripslashes() uses get_magic_quotes_gpc(), which is a deprecated function.
- PHP 7.4 is now strict about the order of the parameters in implode($glue, $array). Perch core uses the alternative order in multiple files.
- money_format() is now deprecated. It is used for formatting currency values with the format attribute.
There is also a mysql 8 compatibility issue as it appears not to support using [[:<:]][[:>:]] for word boundary in regex expressions. This affects the content search handlers and the contains / !contains filters, which can be found in the following classes: