Re: save RMan [-> tiff] in gv

[slevy]

It looks like this "ftruncate" business is dead code -- probably dates
from the time when the rib driver could only write to stdout.  Note
the lseek(1, ...) and ftruncate(1, ...) -- those "1"s mean they're trying
to truncate standard output, not the RIB stream!

I guess this means you can just ignore the error -- it won't affect the
.rib file.

That code should be removed though.