mycrypt was abandoned by its developers in 2007. The package in Debian is
from 2009. It has been removed from RHEL.
This is already unacceptable. But it would be an insult to the idea of
"security" to include mcrypt in PHP 7.
The vote to remove mcrypt is at present tied roughly 13:13. If you have a
vote and haven't used it yet, I urge you to consider doing so. Voting ends
tomorrow 2015-02-09 at 23:00 CET
https://wiki.php.net/rfc/removal_of_dead_sapis_and_exts#extmcrypt