martin@magni:~/src/msoak$ cat Makefile
LDFLAGS += -lutil -lm
CFLAGS += -Wall -Wextra -Wpedantic
PREFIX ?= /usr/local
DESTDIR ?=

all: msoak

.PHONY: install
install:
	install -d $(DESTDIR)$(PREFIX)/bin
	install -m 755 msoak $(DESTDIR)$(PREFIX)/bin

.PHONY: uninstall
uninstall:
	rm -f $(DESTDIR)$(PREFIX)/bin/msoak

.PHONY: clean
clean:
	rm -f msoak
martin@magni:~/src/msoak$ make
cc -Wall -Wextra -Wpedantic  -lutil -lm  msoak.c   -o msoak
/usr/bin/ld: /tmp/ccdvwPeY.o: in function `hsv_to_rgb':
msoak.c:(.text+0xc4): undefined reference to `trunc'
/usr/bin/ld: /tmp/ccdvwPeY.o: in function `main':
msoak.c:(.text+0x615): undefined reference to `forkpty'
collect2: error: ld returned 1 exit status
make: *** [<builtin>: msoak] Error 1
martin@magni:~/src/msoak$ cc -Wall -Wextra -Wpedantic   msoak.c -lutil -lm -o msoak
martin@magni:~/src/msoak$ echo $?
0