run the following command (requires ag , although advanced grep versions should be able to run it, after all, it's just a regular expression: $ ag '(\$[0-9a-zA-Z_]+|\))(\[['\''"\w$]+\])?{[^\n=}]+}' \ lib/h5p h5p --php Verify that you get THREE matches, all them are false-positives corresponding to regular expressions. lib/h5p/h5p.classes.php 1135: if (preg_match('/^(-?[a-z]+){1,7}\.json$/i', $languageFile) === 0) { 2083: $this->relativePathRegExp = '/^((\.\.\/){1,2})(.*content\/)?(\d+|editor)\/(.+)$/'; 2780: !preg_match('/^localhost$|^127(?:\.[0-9]+){0,2}\.[0-9]+$|^(?:0*\:)*?:?0*1$/i', $_SERVER['REMOTE_ADDR']))) { Using moodle-docker (or any >= PHP7.4 RC4 installation) install phpunit (init.php). Verify that there isn't any PHP notice/warning related with h5p stuff. (Be warned that there may be lots of notices/warnings/errors, here we are only interested in the h5p ones). Run phpunit (with that PHP7.4 version). Verify that there isn't any PHP notice/warning related with h5p and curly braces. (Be warned that there are lots of notices/warning/errors and failures, here we are only interested in the h5p ones). Verify that travis is passing for php71 and php73 (specifically h5p ones).