I am trying to add yasm to the jam rules so I can compile asm sources using it. I added a actions like so actions assemble_yasm { yasm -f elf -o $(1) $(2) } then added to the case statement in Objects case .nasm : assemble_yasm $(<) : $(>) ; $(1) is fine (the output dir/file) but $(2) seems to be the output dir/source file How do I get $(2) to be the source dir/file -- Cheers David