readonly_exec + phar archives seems to not work

[ZetaTwo]

Apr 18 13:37:47 helpdesk snuffleupagus[39409]: [snuffleupagus][0.0.0.0][readonly_exec][log] Error while accessing phar:///var/www/html/osticket/upload/include/plugins/auth-oauth2.phar/plugin.php: No such file or directory in phar:///var/www/html/osticket/upload/include/plugins/auth-oauth2.phar/plugin.php on line 3

I suspect that sp tries to do something with the fake path that PHP provides for the file inside the phar archive. I guess phar:// files require special handling to split on the (last?/first?) .phar part and check if that file has the right properties, etc.