That's interesting. Author probably wants to use `private` for those target-local variables, though. For example, R: .SHELLFLAGS := -e R: SHELL := Rs

That's interesting. Author probably wants to use `private` for those target-local variables, though. For example, R: .SHELLFLAGS := -e R: SHELL := Rscript R: greeting = "bonjour" message(paste0(greeting, ", R!")) Everything that target `R` depends on will also have SHELL and .SHELLFLAGS over-ridden. If `R` depends on some data generated by another program, it probably wants to be built and executed with the default SHELL (or another shell, perhaps). R: private .SHELLFLAGS := -e R: private SHELL := Rscript R: greeting = "bonjour" message(paste0(greeting, ", R!")) Now, `R`'s dependencies will be generated with the makefile's defaults. Usually I prefer to build up richer stages like this using the system shell anyway, though. Build a target which in turn is executed by the shell normally to traverse the next edge in the graph. But I can see how this mechanism has its uses. See also https://www.gnu.org/software/make/manual/html_node/Target_002dspecific.html https://www.gnu.org/software/make/manual/html_node/Target_00...