problem building gerris on armel: Illegal instruction

[Drew Parsons]

Dear armel experts,
cc: Debian Science, Gerris upstream

gerris is FTBFS failing to build from source on armel, see
https://buildd.debian.org/build.php?pkg=gerris
https://buildd.debian.org/fetch.cgi?&pkg=gerris&ver=0.9.2%
2Bdarcs081022-dfsg.1-3&arch=armel&stamp=1238595409&file=log

All other architectures have built successfully (besides s390, a
different problem which I have just patched).

The symptom in the log looks like:
make[4]: Entering directory `/build/buildd/gerris-0.9.2
+darcs081022-dfsg.1/doc/examples'
/bin/sh ../../libtool --silent --mode=link cc  -I../../src -I/usr/include -DG_LOG_DOMAIN=\"Gfs-tools\" -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include -DFTT_2D=1 \
	classes.c -o classes ../../src/libgfs2D.la -L/usr/lib -lgts -Wl,--export-dynamic -lgmodule-2.0 -ldl -lglib-2.0 -lm 
./classes > gfs.lang
/bin/sh: line 1:  8434 Illegal instruction     ./classes > gfs.lang
make[4]: *** [gfs.lang] Error 132
make[4]: Leaving directory `/build/buildd/gerris-0.9.2+darcs081022-dfsg.1/doc/examples'
make[3]: *** [all-recursive] Error 1


It's not clear to me why an "Illegal instruction" is occurring.  From
the previous cc line, ./classes would appear to have been compiled
successfully, so it should exist.  There's nothing obviously machine
specific in classes.c (../../src/libgfs2D.la could be a different
matter).

The gerris source is available in git, see
http://git.debian.org/?p=debian-science/packages/gerris.git/.git;a=summary

Please advise!

Drew