2 # A target must be rebuilt when a non-existence dependency exists.
4 >all.do printf 'redo-ifchange a\n'
5 >a.do printf 'test -e b || redo-ifcreate b\ndate +%s\n'
8 <a read -r timestamp_a1
14 <a read -r timestamp_a2
16 test ${timestamp_a2} -gt ${timestamp_a1}