[GiNaC-list] Bug? Segmentation while inverting a matrix

Hi, i'm getting a segmentation fault while inverting a matrix (the matrix itself is invertable, i checked with the symbolic package for octave). Can anyone give me some pointers why this is happening? Is the matrix ill-formed in some way or is this a bug? Many thanks in advance! I'm running archlinux (Kernel 4.14.12), my compiler is g++ 7.2.1, the GiNaC version i'm using is 1.7.2. Attached is a sample listing which produces the error (at least on my system). Greetings, Patrick