Some more information. Attached is the script I originally used. Here's the output of an interactive SSH session where I try to unlock the device(s) using the normal cryptroot-unlock command:
[1002]anarcat@curie:~255$ unlock-marcos To unlock root partition, and maybe others like swap, run `cryptroot-unlock` To unlock root-partition run unlock BusyBox v1.22.1 (Debian 1:1.22.0-19+b3) built-in shell (ash) Enter 'help' for a list of built-in commands. ~ # cryptroot-unlock Please unlock disk Crucial_CT480M500SSD1-crypto: cryptsetup: Crucial_CT480M500SSD1-crypto set up successfully ~ # ~ # ~ # Connection to 192.168.0.3 closed by remote host. Connection to 192.168.0.3 closed. cryptsetup lied: at this point there's still a password prompt (plymouth) on the console, which I need to fill in.