1 subdirmk: warning (single-char-var): ./Dir.sd.mk:8: possibly confusing unbracketed single-char $-expansion
2 subdirmk: warning (local+global): saw both WARN and &WARN
3 saw WARN at ./Dir.sd.mk:6
4 saw WARN at ./Dir.sd.mk:9
5 saw &WARN at ./Dir.sd.mk:7
6 saw &WARN at ./Dir.sd.mk:10
7 saw &WARN at ./Dir.sd.mk:11
8 subdirmk: warning (unknown-warning): ./sub/dir/Dir.sd.mk:3: attempt to suppress unknown warning(s) `some-unknown-warning'