2 # A target must not be rebuilt when a dependency of a dependency does not change.
3 >all.do printf 'redo-ifchange a\n'
4 >a.do printf 'redo-ifchange b\ndate +%s\n'
5 >b.do printf 'redo-ifchange c\ndate +%s\n'
9 <a read -r timestamp_a1
10 <b read -r timestamp_b1
16 <a read -r timestamp_a2
17 <b read -r timestamp_b2
19 test ${timestamp_a2} -eq ${timestamp_a1}
20 test ${timestamp_b2} -eq ${timestamp_b1}