Makefile Arguments (GNU make)
From Get docs
Make/docs/latest/Makefile-Arguments
9.1 Arguments to Specify the Makefile
The way to specify the name of the makefile is with the ‘-f’ or ‘--file’ option (‘--makefile’ also works). For example, ‘-f altmake’ says to use the file altmake as the makefile.
If you use the ‘-f’ flag several times and follow each ‘-f’ with an argument, all the specified files are used jointly as makefiles.
If you do not use the ‘-f’ or ‘--file’ flag, the default is to try GNUmakefile, makefile, and Makefile, in that order, and use the first of these three which exists or can be made (see Writing Makefiles).
