[FWTools] FWTools 1.0.0a7 Problems on Linux

[Ed McNierney]

Frank et al. -

A few weeks ago I reported some problems with FWTools 1.0.0a7 running on
my Red Hat ES 3 systems.  Frank generously spent some time looking into
it, and I've been working on the problems on and off ever since.  I
don't know much, but here's what I do know (or think I know):

1. The problems seem to be GDAL-based, popping up in tools using GDAL.
I particularly ran into trouble working with GeoTIFF data sets, but
that's really all I was testing on so I can't say whether these seemed
to be GeoTIFF-specific.  Tools would hang with 100% CPU use, or crash.

2. Various debug tools gave me reason to suspect libtiff and/or the
compiler runtime libraries.  RH ES 3 ships with libtiff 3.5 which might
have been a problem.  However, I upgraded various TIFF and related
libraries, then selected compiler libraries, then finally upgraded the
whole compiler suite to 3.4.5.  Nothing fixed the problem.

3. I then put FWTools on a back burner and did a refresh and rebuild of
my MapServer source tree, including GDAL and its utilities.  I continued
to have exactly the same problems.

4. Since I was going to do it anyway, and since Frank suspected problems
with "older Red Hat" systems, I upgraded to RH EL 4, Update 2.  This
made the problems go away, and all the tools work fine.

Unfortunately, I don't know what the problem really was and I can't
continue to investigate now that it's "fixed".  But I'd add this data to
the belief that RH ES 3 (and perhaps other releases) may be troublesome,
while RH ES 4, Update 2, seems to work fine.

At the same time I also reported that the link to the FWTools
distribution had a typo and linked to a file ending in ".tar.tar"
instead of ".tar.gz"  When I tried later that day (on a different
system) the problem had already been "fixed".  I have since discovered
that there is something wrong with my browser on one particular machine,
and it was that browser that was mangling the filename (it does it to
anything ending in ".tar.gz".  There actually wasn't (and isn't) any
problem on the FWTools site at all.

Thanks to Frank for the help!

	- Ed

Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
Phone: +1 (978) 251-4242
Fax: +1 (978) 251-1396
ed at topozone.com