only display the first few erros, and fail if everything didn't get

displayed..

Makefile

@@ -8,6 +8,6 @@ _ggatehttp=	ggatehttp
 .PHONY: devtest
 
 devtest:
-	find [gst]* -type f -name '*.c' -o -name 'Makefile*' -o -name '*.sh' -o -name '*.8' | entr sh -c 'make -j 4 && make install -j 4 && (kyua test -k /usr/tests/Kyuafile sys/geom/class/gate || (cd /usr/tests && kyua report --verbose))'
+	find [gst]* -type f -name '*.c' -o -name 'Makefile*' -o -name '*.sh' -o -name '*.8' | entr sh -c '(set -o pipefail; make -j 4 | head -n 30) && make install -j 4 && (kyua test -k /usr/tests/Kyuafile sys/geom/class/gate || (cd /usr/tests && kyua report --verbose))'
 
 .include <bsd.subdir.mk>