While it's not quite the same, we can create a short makefile. vixen: rudolph prancer dasher cupid blitzen echo vixen dancer : vixen donder blitzen rudolph cupid dasher echo dancer comet: vixen cupid prancer rudolph echo comet donder: comet vixen dasher prancer cupid blitzen rudolph echo donder cupid: prancer echo cupid blitzen: cupid dasher echo blitzen rudolph: cupid prancer echo rudolph dasher: rudolph prancer ech…
There's also the dedicated unix utility "tsort" (https://en.wikipedia.org/wiki/Tsort) although actually your makefile is more succinct.