Matlab 2011b hangs on startup, but runs fine with no desktop

I am running Matlab 2011b on a Debian Linux server, accessing it using X11 forwarding/ssh from a Mac (Snow Leopard). This was working fine until the server was updated from Debian Linux Sid to Squeeze (stable).

Running matlab from the Mac now displays the splash screen but then hangs. I can run matlab with no graphics (-nodesktop or -nojvm).

X11 forwarding is working perfectly. Of note, the debian server has no native X server or java installation. There is also a local Matlab (same version) on the Mac I'm using, which works fine. I've checked everything I can think of and I'm completely stumped here. Suggestions welcome.

[Daniel Shub]

Have you tried using trusted X11 forwarding (-Y instead of -X)?

[Image Analyst]

Or reinstalling? Or calling the Mathworks which gives free installation help? Or upgrading to the latest R2012b version?

[Jason Ross]

It's not exactly clear what's going wrong from your description:

• Are you trying to forward the X display from the Debian server to the Mac? Or X display from Mac to Debian? "I am running Matlab 2011b on a Debian Linux server, accessing it using X11 forwarding/ssh from a Mac" is ambigious as to which direction things are going. I assume MATLAB is on the Linux machine and you are trying to forward the display to the Mac.
• Are you trying to start MATLAB on the Mac and that MATLAB is hanging? You say "Running matlab from the Mac now displays the splash screen but then hangs", then later say "There is also a local Matlab (same version) on the Mac I'm using, which works fine."
• When you say "X11 forwarding works perfectly", do you mean that you can set the X display on the Debian host and then open xterm, xeyes, xclock, and so on?
• When you start MATLAB with -nodesktop / -nojvm, are you talking about starting it on the Mac, on the Linux server, or both?

But to me, it seems like something was lost or misconfigured in the upgrade on the Debian server. The second place I'd look was to upgrade the X11 / XQuartz things on the Mac. There have been significant changes to X11 support on Mac as each new OS has come out.

[Catherine Schevon]

I've tried both -X and -Y.

Upgrading is not an option (university license).

I did try reinstalling.

The idea is to forward the X display from the Debian server (where matlab is running) to the Mac.

I am starting matlab from an X11 terminal session on the mac: open X11 terminal, log into the server, start matlab. The graphics display is then forwarded to the mac. When I run "xclock" from the same terminal session, the forwarding operates perfectly by which I mean: An X window opens on the Mac, and displays xclock. I don't need to manually set any X display variables.

I figured that most likely a software package was upgraded on the debian server so as to be no longer compatible with some deep assumption in Matlab, but I have no chance of figuring that out on my own without spending way more time than I have on a fishing trip. I was hoping that this had happened to someone else and that I could benefit from the experience.

I've tried to call Mathworks installation help before. It's a great way to blow a few hours.

Answer 1

[Jason Ross]

Given the clarifications, I'd check the logs on both machines, and try and isolate which end of the connection is having trouble.

On the Linux machine, check in /var/log. There might be an Xorg log and also a system log. Also check on the Mac in the same areas. There might be some insight there.

I'd also try the same on another machine -- either one running Mac OSX, or another Linux box, or even Windows running a X emulator.

Can you start something like a VNC server on the Debian box and start MATLAB there in the VNC session? This might not be possible given your earlier comment about the lack of an X server running on the host (it's not clear if the packages are there and not being used, or not installed at all)

You can also turn up the verbosity on your ssh connection, as well. That might shed some light on what's missing.

[Catherine Schevon]

Thanks, I'll try your suggestions. X is not installed on the debian box.