GNU Parallel Bug Reports first instance hanging when using with matlab

[Jason Patton]

I discovered a strange behavior when porting a script over to a new
machine (with a newer version of parallel). The first instance of
matlab called with parallel will hang with no output. I was able to
narrow down this behavior to starting with version 20150622. Here's
some output (from both versions 20150522 and 20150622) that maybe
helps to explain what I mean:

--- version 20150522 (works) ---
$ parallel-20150522 'matlab -nodisplay -nodesktop -singleCompThread -r
exit' ::: 1 2 3

                            < M A T L A B (R) >
                  Copyright 1984-2015 The MathWorks, Inc.
                   R2015a (8.5.0.197613) 64-bit (glnxa64)
                             February 12, 2015


To get started, type one of these: helpwin, helpdesk, or demo.
For product information, visit www.mathworks.com.


Academic License


                            < M A T L A B (R) >
                  Copyright 1984-2015 The MathWorks, Inc.
                   R2015a (8.5.0.197613) 64-bit (glnxa64)
                             February 12, 2015


To get started, type one of these: helpwin, helpdesk, or demo.
For product information, visit www.mathworks.com.


Academic License


                                       < M A T L A B (R) >
                             Copyright 1984-2015 The MathWorks, Inc.
                              R2015a (8.5.0.197613) 64-bit (glnxa64)
                                        February 12, 2015


To get started, type one of these: helpwin, helpdesk, or demo.
For product information, visit www.mathworks.com.


Academic License
-------------------------------------

--- version 20150622 (have to Ctrl-C) ---
$ parallel-20150622 'matlab -nodisplay -nodesktop -singleCompThread -r
exit' ::: 1 2 3

                            < M A T L A B (R) >
                  Copyright 1984-2015 The MathWorks, Inc.
                   R2015a (8.5.0.197613) 64-bit (glnxa64)
                             February 12, 2015


To get started, type one of these: helpwin, helpdesk, or demo.
For product information, visit www.mathworks.com.


Academic License


                            < M A T L A B (R) >
                  Copyright 1984-2015 The MathWorks, Inc.
                   R2015a (8.5.0.197613) 64-bit (glnxa64)
                             February 12, 2015


To get started, type one of these: helpwin, helpdesk, or demo.
For product information, visit www.mathworks.com.


Academic License

^C
-------------------------------------

By messing with echos or IO redir, you should see that it's the first
matlab instance called that hangs. Also, I'm just executing "exit" in
this case for testing and small output, matlab will hang no matter
what command line parameters are passed.

FWIW, I've tested this on both CentOS 7 and Fedora 22, both running
Matlab R2015a. Let me know if I can help to test any fix.

Jason Patton