Re: Error on Linux Platform

[Nelson Minar]

[about Swarm on Linux]

Joannes writes:

>We have now tried to install it on Linux and SWARM compiled without any 
>problems or errors. When we run any application, we get the BLT windows 
>with the parameters and the GO/STOP/QUIT option, but if we try to give to 
>GO commmand, we get a 'segmentation fault' error.

Where exactly does this error occur? Do you get any messages on
stdout? Can you run under a debugger and send us a stack trace? One
problem you'll definitely have under Linux is a bug in BLT, in
particular bltGrAxis.c. You need a version of libBLT built without -O
on that file. If this is the problem, it will print some error about a
failed assertion in BLT, precisely on the second dot added to a graph.

[maybe it's getting to be time to have a FAQ.]

Kerry says:
>That's the same problem I've been having running Swarm on Linux.  I think
>I've figured out why but I won't know for sure until tomorrow.  When you
>upgrade the gcc compiler to 2.7.2 you also have to upgrade the C libraries,
>the binary utilities and ld.so.  Part of the problem is that 2.7.2 compiles
>in ELF and 2.6.3 compiles in a.out.  The ELF HOW-TO gives the step-by-step
>on upgrading all of these libraries.  After you follow the steps, be sure to
>do a final ldconfig after making the cpp link.  

This is another problem, the variety of systems that are defined as
'Linux'. I've done all my Linux development under Slackware 2.1 (about
a year old) and RedHat 2.0 (2.1 is current - all ELF). The ELF
switchover has caused a lot of minor problems. My advice for people
wanting to use Linux is to go with RedHat 2.1. It's a nice stable
system, and you can even get support for it if you want.

With RedHat 2.1 the two problems you'll have are needing to link
against -lieee (fixed in libc 5.2 and above, btw) and that problem
with BLT. Again, if there are enough Linux people around I'm happy to
provde ELF shared versions of tcl, tk, blt, and a static tclobjc that
I know work. tcl and tk are no big deal, but I don't know of good
binary distributions of blt and tclobjc.

>After that's done, you probably need to upgrade your kernel.  I and others
>have had trouble compiling with 2.7.2 using the 1.2.X kernel.

Hmm, I've never heard that before. 2.7.2 has trouble building the
1.2.x kernels themselves because those kernels couldn't compile under
ELF, but once you have the kernel binary (there's a patch for
compiling the kernel), things I've done have worked. I'm using 1.3.45
right now, myself, but developed swarm under 1.2.13 for awhile.