1make -r -f /dev/null -V MAKEFLAGS 2 -r -k -d 0 3 4make -: 5usage: make [-BeikNnqrSstWwX] 6 [-C directory] [-D variable] [-d flags] [-f makefile] 7 [-I directory] [-J private] [-j max_jobs] [-m directory] [-T file] 8 [-V variable] [-v variable] [variable=value] [target ...] 9*** Error code 2 (ignored) 10 11make -r -f /dev/null -- -VAR=value -f /dev/null 12make: don't know how to make -f (continuing) 13`/dev/null' is up to date. 14 15Stop. 16make: stopped making "-f /dev/null" in unit-tests 17*** Error code 1 (ignored) 18 19make -? 20usage: make [-BeikNnqrSstWwX] 21 [-C directory] [-D variable] [-d flags] [-f makefile] 22 [-I directory] [-J private] [-j max_jobs] [-m directory] [-T file] 23 [-V variable] [-v variable] [variable=value] [target ...] 24*** Error code 2 (ignored) 25 26exit status 0 27