Comment 41 for bug 216990

Attached is an alternate solution for this issue, following Colin's suggestion of a 'missingok' option.

I'm not altogether happy with this as a solution because up until now the module option list has been entirely pass-through by libpam, but the previous fix I proposed is also inadequate because all logging that uses the 'auth' facility, including debug logging, is written to /var/log/auth.log by default, so lowering the log severity of these messages is insufficient to reduce the log spam; and dropping all such log messages for all 'optional' modules would be a significant hindrance to debugging.

So I think we should go ahead with this second patch under the circumstances, and solve this problem correctly for intrepid using module hooks.