Hello David Bremner, I just tried to reproduce this crash, while I am not involved in packaging and without knowledge of bliss.
I always this output: benutzer@debian:~$ bliss myciel3.col Generator: (2,4)(3,5)(7,9)(8,10) Generator: (1,2)(3,4)(6,7)(8,9) Nodes: 6 Leaf nodes: 4 Bad nodes: 0 Canrep updates: 1 Generators: 2 Max level: 2 |Aut|: 10 Total time: 0.00 seconds benutzer@debian:~$ Do you still get this crash? Is my bliss command line wrong? Maybe something got lost in the input file, so you could attach it to the email? Is the backtrace you copied all of the output or did you remove the frame in function main? Kind regards, Bernhard