Trouble Building llvm-gcc-4.2

I'm still trying to debug the validator buildbot.

I'm getting this error when building some variants of llvm-gcc-4.2:

/bin/sh ../../src/gcc/mkconfig.sh bconfig.h
gcc -c -g -DIN_GCC -W -Wall -Wwrite-strings -Wstrict-prototypes
-Wmissing-prototypes -pedantic -Wno-long-long -Wno-variadic-macros
-Wno-overlength-strings -Wold-style-definition -Wmissing-format-attribute
-fno-common -DHAVE_CONFIG_H -DGENERATOR_FILE -I. -Ibuild -I../../src/gcc
-I../../src/gcc/build -I../../src/gcc/../include
-I../../src/gcc/../libcpp/include -I../../src/gcc/../libdecnumber
-I../libdecnumber
-I/tmp/ptmp/dag/buildbot/slaves/llvm-validate/llvm-validate-release-egypt-linux/build/llvm-initial/obj/include
-I/tmp/ptmp/dag/buildbot/slaves/llvm-validate/llvm-validate-release-egypt-linux/build/llvm-initial/src/include
-DENABLE_LLVM
-I/tmp/ptmp/dag/buildbot/slaves/llvm-validate/llvm-validate-release-egypt-linux/build/llvm-initial/obj/../src/include
-DNDEBUG -D_GNU_SOURCE -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS -o
build/errors.o ../../src/gcc/errors.c
build/genmodes -h > tmp-modes.h
/bin/sh: line 1: build/genmodes: No such file or directory
make[4]: *** [s-modes-h] Error 127

Google turned up a gcc bug in which a maintainer explained that doing
a ./configure in the source directory could cause this. Except the buildbot
doesn't do that.

Anyone seen this before and have any idea how to fix it?

                                                  -Dave

Yes, when I didn't have flex installed.
Though gcc's configure script should detect that, shouldn't it?

Best regards,
--Edwin

configure finds flex. I've pointed it to a newer versions. We'll see if that
helps.

                                         -Dave