The problem is not the message "Attention! This core is running with glibc 2.7 but it was compiled with glibc 2.6.1. This can lead to unexpected behaviour. Consider compiling the core yourself or getting a binary compiled with glibc 2.6.1." The problem comes later as that: "[1]+ Violación de segmento mlnet" == "[1]+ Segmentation fault mlnet" or something similar. This happens in Debian Testing and Unstable. We only need a recompilation of mlnet to solve it.