I tried to build Octave 4.2.1 from sources and got the errors listed in the attached file. I tried with both gcc-5.3.0 and gcc-6.3.0 on my Slackware platform with a 2.6.33.4 linux kernel and glibc 2.11.1.
Any idea on what is happening and how can I build Octave 4.2.1 on my machine?