Ugly error adding an alias where the source already exists

[germania]

If I create an alias from me@example.com to you@example.com, then attempt to create an alias from me@example.com to him@example.com, the following error is shown to the user, rather than a friendly "aliases cannot have multiple destinations" type error:

NameError at /user/alias/new
undefined local variable or method `row' for #<Connection:0x000000160f61b0 @con=#Mysql:0x000000160f6188>

/mailadmin-0.1.1/lib/connection.rb in get_alias_by_name
return row[0] if row = q.fetch_row
/mailadmin-0.1.1/lib/mailadmin.rb in block in <top (required)>
e_src = @con.get_alias_by_name(src_email, :src)