The makefile in tutorials/introduction-to-groups-and-communicators/code uses incorrect target names. The targets are currently named split and groups, but the build outputs (as specified in the EXECS variable) are comm_split and comm_groups.

EXECS=comm_groups comm_split
MPICC?=mpicc

all: ${EXECS}

split: comm_split.c
	${MPICC} -o comm_split comm_split.c

groups: comm_groups.c
	${MPICC} -o comm_groups comm_groups.c

clean:
	rm -f ${EXECS}

Should rename the makefile targets from split → comm_split and groups → comm_groups to match the executables?