What steps will reproduce the problem?
1. cd $GOROOT/src && ./make.bash

What is the expected output?

Glorious successful compilation

What do you see instead?

%%%% making libmach %%%%

make: Entering directory `/home/dfc/go/src/libmach'
quietgcc -I"/home/dfc/go/include" -ggdb -O2 -c
"/home/dfc/go/src/libmach/executable.c"
quietgcc -I"/home/dfc/go/include" -ggdb -O2 -c
"/home/dfc/go/src/libmach/fakeobj.c"
quietgcc -I"/home/dfc/go/include" -ggdb -O2 -c
"/home/dfc/go/src/libmach/map.c"
quietgcc -I"/home/dfc/go/include" -ggdb -O2 -c
"/home/dfc/go/src/libmach/obj.c"
cc1: warnings being treated as errors
/home/dfc/go/src/libmach/obj.c:218: warning: comparison is always false due to limited
range of data type

Which compiler are you using (5g, 6g, 8g, gccgo)?

5g

Which operating system are you using?

Linux
Which revision are you using?  (hg identify)

5e185598b8d6+ tip

Please provide any additional information below.

% gcc -v
Using built-in specs.
Target: arm-none-linux-gnueabi
Configured with: ../gcc-4.2/configure --build=i386-pc-linux-gnu
--host=arm-none-linux-gnueabi --target=arm-none-linux-gnueabi --prefix=/opt
--disable-nls --disable-static
--with-as=/home/slug/optware/cs08q1armel/toolchain/arm-2008q1/bin/arm-none-linux-gnueabi-as
--with-ld=/home/slug/optware/cs08q1armel/toolchain/arm-2008q1/bin/arm-none-linux-gnueabi-ld
--enable-languages=c,c++ --disable-multilib --enable-threads --disable-libmudflap
--disable-libssp --disable-libgomp --disable-libstdcxx-pch --enable-shared
--enable-symvers=gnu --enable-__cxa_atexit
Thread model: posix
gcc version 4.2.3