Are you running Debian linux with Maven? Well, if you do and if you have the (bad?) habit to update your packages every now and then, be prepared for a nasty side effect!

Quite recently, the open ssh client package has been updated. This update switched the HashKnownHosts from disabled to enabled. As a result, all new entries in your known_hosts file have a hashed host name and IP. So, you may now wonder why the heck you should care.?

Well if you deploy your Maven stuff with scp, you might get a surprise with new (i.e. unregistered) servers. As you might now, the maven release plugin forks a new mvn process to perform the release. Maven relies, for some unknown reason, to a non hashed host name entry in your know_hosts file. If the entry couldn’t be found, it will ask you if you are sure you want to connect. Oh, see the problem? Yes, the process is forked so you can’t type ‘yes’ :)

Hopefully, you can just edit your /etc/ssh/ssh_config file and disable the HashKnownHosts entry.