No rule to make swift_sections.S.o on Ubuntu 16.04?

Hi,

I am building swift on Power8/LE (after making appropriate changes for
ppc64le) and getting following error while building swift/stdlib

make[2]: Entering directory
'/root/swift-source/build/Unix_Makefiles-ReleaseAssert/swift-linux-powerpc64le'
make[2]: *** No rule to make target
'stdlib/public/runtime/CMakeFiles/section_magic_end-linux-powerpc64le.dir/swift_sections.S.o',
needed by 'lib/swift/linux/powerpc64le/swift_end.o'. Stop.
make[2]: Leaving directory
'/root/swift-source/build/Unix_Makefiles-ReleaseAssert/swift-linux-powerpc64le'
CMakeFiles/Makefile2:1016: recipe for target
'stdlib/public/runtime/CMakeFiles/lib-swift-linux-powerpc64le-swift_end.o.dir/all'
failed
make[1]: ***
[stdlib/public/runtime/CMakeFiles/lib-swift-linux-powerpc64le-swift_end.o.dir/all]
Error 2

I checked the cmake rules but can't seem to get it fixed. Am I missing
anything obvious? Any suggestions?

Thanks in advance!

Best regards,
Atul.