[GRASS5] Re: [GRASSLIST:2259] Re: NVIZ on Cygwin

[Glynn Clements]

Paul Kelly wrote:

> > Unfortunately, almost everything which could possibly go wrong with
> > building NVIZ results in exactly this error message (including the
> > stuff which I've snipped).
> >
> > The only way to track such problems down is to use a debugger (e.g.
> > gdb). If you can try the following, it may provide useful information:
> >
> > 	GRASS:~ > eval `g.gisenv`
> > 	GRASS:~ > gdb /home/Rich/grass/grass-5.0.3/dist.i686-pc-cygwin/etc/nviz2.2/NVWISH2.2
> > 	> run -f /home/Rich/grass/grass-5.0.3/dist.i686-pc-cygwin/etc/nviz2.2/scripts/nviz2.2_script ned_patch -name NVIZ
> > 	[... segmentation fault ...]
> > 	> where
> 
> I tried this, with slightly different results from Richard although they
> don't look any more informative (see below). I used the 5.3 version of
> NVIZ with the latest patches from Bob Covill.

Yesterday, I finally got around to compiling GRASS (5.3, no more than
a week old) on Cygwin, and NVIZ works for me.

FWIW, the Tcl/Tk libraries which I'm using are:

-rwxrwxr-x    1 root     root       568244 Apr  6  2001 libtcl8.0.a
-rwxrwxr-x    1 root     root       791790 Apr  6  2001 libtk8.0.a

c3c3068a82675fe65a1481257abee9d4  libtcl8.0.a
e58da4259572da858fe3721f499382f6  libtk8.0.a

which are from:

-rwxrwxr-x    1 root     root      2002441 Feb  4 01:06 xtcltk8.0.5-CYGWIN_NT-4.0-20010405-1.tar.gz*

b9e35f4d9f13404dc40384d2cdec0b85  xtcltk8.0.5-CYGWIN_NT-4.0-20010405-1.tar.gz

I have both the 8.0.2 and 8.3.4 libraries installed, but the headers
are those from 8.0.2.

I'll try again with 8.3.4.

> Upon giving the above command, an empty (black) Windows command-line
> window appeared; the title bar contained the name of the NVWISH2.2
> program. The message
> ---Type <return> to continue, or q <return> to quit---
> then appeared in the terminal where NVIZ was started and on pressing
> return, the segmentation fault happened.
> 
> What do the two question marks and empty brackets mean? Do the provided
> xtcltk libaries have debugging information? Does anything else need to be
> compiled with debugging turned on?
> 
> Starting program:
> /home/administrator/gbldstat/dist.i686-pc-cygwin/etc/nviz2.2/NVWISH2.2 -f
> /home/administrator/gbldstat/dist.i686-pc-cygwin/etc/nviz2.2/nviz2.2_script
> elevation.dem -name NVIZ
> ---Type <return> to continue, or q <return> to quit---
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0x3096f700 in ?? ()
> (gdb) where
> #0  0x3096f700 in ?? ()
> #1  0x00000400 in ?? ()
> (gdb)

The ?? means that the there isn't any function at that address, e.g. 
because:

a) the program jumped to a bogus memory location (e.g. through a
   corrupted function pointer or a corrupted return address),
b) the stack pointer is bogus,
c) the stack has been corrupted, or
d) the libraries were compiled with -fomit-frame-pointer.

-- 
Glynn Clements <glynn.clements at virgin.net>