In D7, we have two copies of the same Bootstrap Agency base theme modified to show on different URLs using ThemeKey.
This works, but whenever a new module is installed, the site crashes and we see the following in the Apache error log:
PHP Fatal error: Cannot redeclare bootstrap_agency_preprocess_page() (previously declared in /sites/all/themes/bootstrap_agency_minimal/template.php:13) in /sites/all/themes/bootstrap_agency/template.php on line 13
This is actually a very similar issue to this , I just couldn't comment on the above and Clive's answer wasn't all that clear to me. Is it better to merge the two functions or rename one of them - as the 2nd answer suggests? And what does merging entail?