www-apps/drupal has hardcoded dependency on pecl-apc, however other accelerators can be used instead: dev-php/xcache dev-php/eaccelerator So we have to: either write a message in post_install phase, or have some virtial accelerator. Reproducible: Always
I've made the dep optional and tried to list all possible accelerators. If I missed any, feel free to reopen the bug and list it so I can add it to the ebuild.