I found a little more information about this. I checkinstalled a more recent version of netgen (properly sed'ing tcl8.6 and tk8.6 to tcl8.5 and tk8.5 in all the Makefiles to prevent stumbling into another bug related to wrong symbols in linkedition) and found the same problem. Alas, it is reported in debian, which even suggest a fix in Ubuntu 15.10 (didn't work for me tough):
I found a little more information about this. I checkinstalled a more recent version of netgen (properly sed'ing tcl8.6 and tk8.6 to tcl8.5 and tk8.5 in all the Makefiles to prevent stumbling into another bug related to wrong symbols in linkedition) and found the same problem. Alas, it is reported in debian, which even suggest a fix in Ubuntu 15.10 (didn't work for me tough):
https:/ /bugs.debian. org/cgi- bin/bugreport. cgi?bug= 782361
It is also reported in netgen itself (sourceforge but tracker): ttps:// sourceforge. net/p/netgen- mesher/ bugs/21/ but with no updates.