https://getgrav.org/blog/macos-bigsur-apache-multiple-php-versions
https://getgrav.org/blog/macos-bigsur-apache-mysql-vhost-apc
pecl uninstall -r imagick && pecl install imagick && \
pecl uninstall -r yaml && pecl install yaml && \
pecl uninstall -r xdebug && pecl install xdebug && \
pecl uninstall -r apcu && pecl install apcu
However, Xdebug version 3.0 (ie, PHP 7.2+) has a simplified syntax and should look like this:
[xdebug] zend_extension="xdebug.so" xdebug.mode=debug