Hi i'm trying to build gnu bash using jam and i have little problems. there is a build tool named 'mkbuiltins' which is built with a BinCommand rule and it builds successfully. This build tool is used to compile .def files to .c files. I tried to add the following to the Jamfile (based on the rc stuff in Jamrules) to have .def files compiled to .c files : BinCommand mkbuiltins : mkbuiltins.c rule MkBuiltinsComp { # MkBuiltins <c file> : <def file> ; # # <c file> and <def file> must be gristed. SetupObjectsDir ; SEARCH on $(2) += $(SEARCH_SOURCE) ; MakeLocate $(1) : $(LOCATE_TARGET) ; Depends $(1) : $(2) mkbuiltins ; LocalClean clean : $(1) ; MkBuiltins1 $(1) : mkbuiltins $(2) ; } actions MkBuiltins1 { $(2[1]) -o $(1) $(2[2-]) } MkBuiltinsComp kill.c : kill.def ; Did i miss something ? How can debug things ? Do i need to grist kill.c and kill.def somewhere ? How to do this btw ? Additionally, i'd need to have the build tool 'mkbuiltins' not present in the distro folder. In fact, it is only used as a bash build tool. Thanks for the help, Jérôme