unencrypting on a different system fails
I've had this happen before: an encrypted volume will unencrypt with losetup and mount fine on the system it was encrypted on, but not another bailing with "must specify file system type" ( usually meaning a bad password, but not the case here ).
the first time this happened was after a large system update, and I was able to chroot from a previous system backup and successfully unencrypt. now I am in the same predicament but have no previous system backup to chroot into.
I've got the encrypted medium (a file) and the correct password and I know the encryption method, but cant unencrypt. so what can I do? whats the issue here?