Axis segfault on Debian Wheezy

I have a problem with axis. I pulled the latest stable branch from git and compiled it on debian wheezy, amd64, with simulator enabled. It worked fine till a week ago. Now I get segfaults on startup:


$ linuxcnc /home/entwicklung/emc2/linuxcnc-dev/configs/sim/axis/axis_mm.ini
LINUXCNC - 2.5.2
Machine configuration directory is '/home/entwicklung/emc2/linuxcnc-dev/configs/sim/axis'
Machine configuration file is 'axis_mm.ini'
Starting LinuxCNC...
/home/entwicklung/emc2/linuxcnc-dev/scripts/linuxcnc: Zeile 687: 9426 Speicherzugriffsfehler $EMCDISPLAY -ini "$INIFILE" $EMCDISPLAYARGS $EXTRA_ARGS
Shutting down and cleaning up LinuxCNC...
Cleanup done
LinuxCNC terminated with an error. You can find more information in the log:
/home/nik/linuxcnc_debug.txt
and
/home/nik/linuxcnc_print.txt
as well as in the output of the shell command 'dmesg' and in the terminal


dmesg says for each call to linuxcnc:

[ 237.373109] axis[4299]: segfault at 2533000 ip 00007f0139064ae0 sp 00007fff7ffaead0 error 4 in libX11.so.6.3.0[7f013901d000+136000]

Any idea what I could do about it?

Hi

If you search this error message, you will see it arises in a whole variety of situations with different software.
There does not seem to be a definitive solution, each application is different.
Some were hardware (video card) related, others application calls to various libraries.

One thing I did note was that it occurs if an application that uses tcl/tk 8.5, is compiled against 8.6.
It will build but has been reported to throw these errors.
Axis is very tcl/tk dependent and uses 8.5 in later versions

www.mail-archive.com/pymol-users@lists.s...ge.net/msg08107.html

I don't know which version wheezy has installed, you may need to look at your build.
Why it would initially work then stop................?

I take it you have not changed something, no matter how unconnected it may seem, that has changed libraries that axis relies upon?

regards

Wheezy comes with tk8.5.

I've made no changes to any library, everything is from the debian repositories.

The funny thing is that it sometimes works. Just no I have it working, it took ~ 30 tries.

Hi

The only other thing I can think of is try running it with DISPLAY=xemc in the .ini file

If that works consistently, consider trying using the software openGL libraries as per the troubleshooting guide in the Wiki and / or the vesa video driver

Some nvidia cards for instance have drivers which can cause huge problem with openGL, triggering SEG_FAULTS when Axis opens.

regards

Thank you, it was the OpenGL part of the NVIDIA driver. But instead of changing the driver to VESA it's sufficient to ssh to localhost:

$ ssh <user>@localhost -X
$ . <linuxcnc>/scrips/rip-environment
$ linuxcnc

And it's working!

Excellent, nice to know my deductive processes were working.

Strange that it is OK through ssh, very often X forwarding causes problems with openGL

But who cares if it works!

Well, it only works with an interactive ssh connection. e.g. this allways failes:

ssh <user>@localhost -X ". <linuxcnc>/scrips/rip-environment; linuxcnc"

It also fails if I call linuxcnc from any other directory than my home folder.