make[1]: Entering directory `/gcc-work/build'
make[2]: Entering directory `/gcc-work/build/libiberty'
make[3]: Entering directory `/gcc-work/build/libiberty/testsuite'
make[3]: Nothing to be done for `all'.
make[3]: Leaving directory `/gcc-work/build/libiberty/testsuite'
make[2]: Leaving directory `/gcc-work/build/libiberty'
make[2]: Entering directory `/gcc-work/build/fixincludes'
make[2]: Nothing to be done for `all'.
make[2]: Leaving directory `/gcc-work/build/fixincludes'
make[2]: Entering directory `/gcc-work/build/intl'
make[2]: Nothing to be done for `all'.
make[2]: Leaving directory `/gcc-work/build/intl'
make[2]: Entering directory `/gcc-work/build/build-mingw32/libiberty'
make[3]: Entering directory `/gcc-work/build/build-mingw32/libiberty/testsuite'
make[3]: Nothing to be done for `all'.
make[3]: Leaving directory `/gcc-work/build/build-mingw32/libiberty/testsuite'
make[2]: Leaving directory `/gcc-work/build/build-mingw32/libiberty'
make[2]: Entering directory `/gcc-work/build/build-mingw32/fixincludes'
make[2]: Nothing to be done for `all'.
make[2]: Leaving directory `/gcc-work/build/build-mingw32/fixincludes'
make[2]: Entering directory `/gcc-work/build/libcpp'
test -f config.h || (rm -f stamp-h1 && make stamp-h1)
make[2]: Leaving directory `/gcc-work/build/libcpp'
make[2]: Entering directory `/gcc-work/build/gcc'
if test -f stage_last ; then \
  LAST=`cat stage_last`; rm $LAST; make LANGUAGES="c gcov.exe gcov-dump.exe c++ d" BOOT_CFLAGS="-g -O2" $LAST; \
else \
  make LANGUAGES="c gcov.exe gcov-dump.exe c++ d" BOOT_CFLAGS="-g -O2" stage1_build; \
fi
rm: cannot remove `stage2_build': No such file or directory
make[3]: Entering directory `/gcc-work/build/gcc'
make CC=" stage1/xgcc.exe -Bstage1/ -B/mingw/mingw32/bin/" CC_FOR_BUILD=" stage1/xgcc.exe -Bstage1/ -B/mingw/mingw32/bin/" \
	 STAGE_PREFIX=stage1/ \
	 ADAFLAGS="" CFLAGS="-g -O2" LDFLAGS="" WARN_CFLAGS="\$(GCC_WARN_CFLAGS)" STRICT_WARN="-pedantic -Wno-long-long -Wno-variadic-macros -Wold-style-definition -Wmissing-format-attribute  -Wno-format" libdir=/mingw/lib LANGUAGES="c gcov.exe gcov-dump.exe c++ d" MAKEINFO="makeinfo" MAKEINFOFLAGS="--no-split" MAKEOVERRIDES= OUTPUT_OPTION="-o \$@" \
	 CFLAGS="-g -O2" WERROR=" -Wno-format" 
make[4]: Entering directory `/gcc-work/build/gcc'
c++   -g -O2 -DIN_GCC   -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes     -DHAVE_CONFIG_H -I. -Id -I../../source/gcc-4.1.2/gcc -I../../source/gcc-4.1.2/gcc/d -I../../source/gcc-4.1.2/gcc/../include -I../../source/gcc-4.1.2/gcc/../libcpp/include     -Id -I../../source/gcc-4.1.2/gcc/d/dmd -I../../source/gcc-4.1.2/gcc/d -D_GNU_SOURCE=1 -D_DH=1 -DD_NO_TRAMPOLINES=1 -DELFOBJ=1 -DLIBPHOBOS=\"-lgphobos\" -DLIBPHOBOS_PROFILE=\"-lgphobos\" -DD_GCC_VER=41 -Wno-missing-braces -fmessage-length=0 -include ../../source/gcc-4.1.2/gcc/d/dmd/total.h -o d/root.dmd.o -c ../../source/gcc-4.1.2/gcc/d/dmd/root.c
cc1plus.exe: warning: command line option "-Wstrict-prototypes" is valid for C/ObjC but not for C++
cc1plus.exe: warning: command line option "-Wmissing-prototypes" is valid for C/ObjC but not for C++
In file included from ./../../source/gcc-4.1.2/gcc/d/dmd/stringtable.h:19,
                 from ./../../source/gcc-4.1.2/gcc/d/dmd/total.h:25,
                 from <command line>:1:
./../../source/gcc-4.1.2/gcc/d/dmd/lstring.h:23: warning: ignoring #pragma warning 
./../../source/gcc-4.1.2/gcc/d/dmd/dchar.h:155: warning: unused parameter 'pstart'
./../../source/gcc-4.1.2/gcc/d/dmd/dchar.h:158: warning: unused parameter 'pstart'
../../source/gcc-4.1.2/gcc/d/d-gcc-real.h: In member function 'const real_value& real_t::rv() const':
../../source/gcc-4.1.2/gcc/d/d-gcc-real.h:35: warning: type-punning to incomplete type might break strict-aliasing rules
../../source/gcc-4.1.2/gcc/d/d-gcc-real.h: In member function 'real_value& real_t::rv()':
../../source/gcc-4.1.2/gcc/d/d-gcc-real.h:36: warning: type-punning to incomplete type might break strict-aliasing rules
./../../source/gcc-4.1.2/gcc/d/dmd/module.h: At global scope:
./../../source/gcc-4.1.2/gcc/d/dmd/module.h:45: warning: unused parameter 'sc'
./../../source/gcc-4.1.2/gcc/d/dmd/cond.h:31: warning: 'struct Condition' has virtual functions but non-virtual destructor
./../../source/gcc-4.1.2/gcc/d/dmd/cond.h:45: warning: 'struct DVCondition' has virtual functions but non-virtual destructor
./../../source/gcc-4.1.2/gcc/d/dmd/cond.h:56: warning: 'struct DebugCondition' has virtual functions but non-virtual destructor
./../../source/gcc-4.1.2/gcc/d/dmd/cond.h:68: warning: 'struct VersionCondition' has virtual functions but non-virtual destructor
./../../source/gcc-4.1.2/gcc/d/dmd/cond.h:81: warning: 'struct StaticIfCondition' has virtual functions but non-virtual destructor
./../../source/gcc-4.1.2/gcc/d/dmd/cond.h:91: warning: 'struct IftypeCondition' has virtual functions but non-virtual destructor
../../source/gcc-4.1.2/gcc/d/dmd/root.c: In member function 'virtual char* Object::toChars()':
../../source/gcc-4.1.2/gcc/d/dmd/root.c:196: warning: deprecated conversion from string constant to 'char*''
../../source/gcc-4.1.2/gcc/d/dmd/root.c: In static member function 'static char* FileName::ext(const char*)':
../../source/gcc-4.1.2/gcc/d/dmd/root.c:529: error: duplicate case value
../../source/gcc-4.1.2/gcc/d/dmd/root.c:526: error: previously used here
../../source/gcc-4.1.2/gcc/d/dmd/root.c: In static member function 'static int FileName::exists(const char*)':
../../source/gcc-4.1.2/gcc/d/dmd/root.c:803: warning: comparison between signed and unsigned integer expressions
../../source/gcc-4.1.2/gcc/d/dmd/root.c: In member function 'int File::exists()':
../../source/gcc-4.1.2/gcc/d/dmd/root.c:1251: warning: comparison between signed and unsigned integer expressions
make[4]: *** [d/root.dmd.o] Error 1
make[4]: Leaving directory `/gcc-work/build/gcc'
make[3]: *** [stage2_build] Error 2
make[3]: Leaving directory `/gcc-work/build/gcc'
make[2]: *** [quickstrap] Error 2
make[2]: Leaving directory `/gcc-work/build/gcc'
make[1]: *** [all-gcc] Error 2
make[1]: Leaving directory `/gcc-work/build'
make: *** [all] Error 2


My configuration line is as follows
Using built-in specs.
Target: mingw32
Configured with: ../../source/gcc-4.1.2/configure --prefix=/mingw --host=mingw32 --target=mingw32 --program-prefix= --with-as=/mingw/bin/as.exe --with-ld=/mingw/bin/ld.exe --with-gcc --with-gun-ld --with-gnu-as --enable-threads --disable-nls --enable-languages=c,c++,d --disable-win32-registry --disable-shared --without-x --enable-interpreter --enable-hash-synchronization --enable-libstdcxx-debug
Thread model: win32
gcc version 4.1.2