Not able to generate assembly files

[c.calderon]

Hi all,
 
I trying to install GNUProlog in a linux workstation...but i run into
the following error when I try to compile *.pl files:
 
I execute the following command:
gplc --verbose writechars.pl
 
and get this:
 
Copyright(C) 1999,2000 Daniel Diaz
GNU Prolog comes with ABSOULTELY NO WARRANTY 
you may redistribute copies of GNU Prolog
under the terms of the GNU General Public License
 
For more information about these matters, see the files named COPYING.
 
Path used: /usr/lib/gprolog-1.2.1
 
***Compiling
pl2wam -o /tmp/gplc5wq05c.wam writechars.pl
writechars.pl: 126--136 warning: singlenton variables [In, StreamInput]
for send/0
wam2ma -o /tmp/gplcsq6kSc.ma /tmp/gplc5wq05c.wam
delete /tmp/gplc5wq05c.wam
ma2asm -o /tmp/gplcHt30tN.s /tmp/gplcsq6kSc.ma
delete /tmp/gplcsq6kSc.ma
as -o /tmp/gplccpuUFq.o /tmp/gplcHt30tN.s
 
error trying to execute as: No such file or directory compilation failed
 
deleting temporary files before exit
delete /tmp/gplcHt30tN.s
delete /tmp/gplccpuUFq.o
 
--------------------------
 
my Prolog version is gprolog-1.2.1-1