Problem crosscompiling for MIPS (YLWRAP undefined!)

[Andreas Jaeger <aj at suse dot de>]

I'm trying to do a cross build from i686-linux to mipsel-linux of the
current binutils CVS version and got a build failure in the gas subdirectory.

config.status contains:
# /cvs/binutils-gdb-ln/gas/configure  --host=i686-pc-linux-gnu --target=mipsel-linux --prefix=/opt/mips-cross --srcdir=/cvs/binutils-gdb-ln/gas --with-stabs --with-gnu-as --with-gnu-ld --enable-shared=no --enable-static=yes --enable-build-warnings --disable-nls --cache-file=../config.cache


Running make aborts with:
make[2]: Entering directory `/builds/sourceware-src/mips-cross/gas'
/bin/sh  "`if [ -f ../bison/bison ] ; then echo ../bison/bison -y -L../bison/bison ; else echo bison -y ; fi`" /cvs/binutils-gdb-ln/gas/itbl-parse.y y.tab.c itbl-parse.c y.tab.h itbl-parse.h -- -d
bison -y: bison -y: No such file or directory

The problem is this rule in Makefile.am:
itbl-parse.c itbl-parse.h: $(srcdir)/itbl-parse.y
        $(SHELL) $(YLWRAP) "$(YACC)" $(srcdir)/itbl-parse.y y.tab.c itbl-parse.c y.tab.h itbl-parse.h -- -d

YLWRAP seems to be undefined - and I don't see any place where it gets
a value.

In other Makefile.in files, there's a line:
YLWRAP = $(srcdir)/../ylwrap

but this one is missing in gas/Makefile.in[1].  Is this a bug in automake
or where lies the problem?

Andreas

Footnotes: 
[1]  And adding it to Makefile.in solves the problem - but this is not
     the proper solution.
-- 
 Andreas Jaeger
  SuSE Labs aj@suse.de
   private aj@arthur.inka.de