Trying to create the table structure for a fresh aurweb install with 'mysql -uaur -p AUR < aur-schema.sql' I get the following error from the mysql console:

ERROR 1071 (42000) at line 23: Specified key was too long; max key length is 767 bytes

Used MySQL version is:
mysql Ver 15.1 Distrib 10.0.22-MariaDB, for Linux (x86_64)

Solution 1:
Removing the unique constraint on the Email field solves the issue but might create problems when creating users.

Solution 2:
Reducing the varchar to from 256 to 255 solves the problem.
But we'd need to check whether anyone already used the current maximum of 256 characters.