The build shows errors (but does not stop) that look like below because of a missing .PHONY rule in make/excludeSrc.make.

cd linux_amd64_compiler2/debug && make -w " LP64=1 "
make[3]: Entering directory `/home/stefank/hg/hsx-gc.clean/build/linux/linux_amd64_compiler2/debug'
make -f vm.make ./precompiled.hpp.gch -w
INFO: ENABLE_FULL_DEBUG_SYMBOLS=1
INFO: /usr/bin/objcopy cmd found so will create .debuginfo files.
INFO: STRIP_POLICY=min_strip
INFO: ZIP_DEBUGINFO_FILES=0
make[4]: Entering directory `/home/stefank/hg/hsx-gc.clean/build/linux/linux_amd64_compiler2/debug'
Generating precompiled header precompiled.hpp.gch
In file included from /home/stefank/hg/hsx-gc.clean/src/os_cpu/linux_x86/vm/atomic_linux_x86.inline.hpp:29:0,
                from /home/stefank/hg/hsx-gc.clean/src/share/vm/runtime/atomic.inline.hpp:32,
                from /home/stefank/hg/hsx-gc.clean/src/share/vm/memory/allocation.inline.hpp:28,
                from /home/stefank/hg/hsx-gc.clean/src/share/vm/utilities/array.hpp:29,
                from /home/stefank/hg/hsx-gc.clean/src/share/vm/memory/universe.hpp:29,
                from /home/stefank/hg/hsx-gc.clean/src/share/vm/code/oopRecorder.hpp:28,
                from /home/stefank/hg/hsx-gc.clean/src/share/vm/asm/codeBuffer.hpp:28,
                from /home/stefank/hg/hsx-gc.clean/src/share/vm/asm/assembler.hpp:28,
                from /home/stefank/hg/hsx-gc.clean/src/share/vm/precompiled/precompiled.hpp:29:
/home/stefank/hg/hsx-gc.clean/src/share/vm/runtime/os.hpp:28:30: fatal error: jvmtifiles/jvmti.h: No such file or directory
compilation terminated.