$> make re
gcc -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include  -lglib-2.0       re.c   -o re
/tmp/ccxas1nI.o: In function `print_uppercase_words':
re.c:(.text+0x21): undefined reference to `g_regex_new'
re.c:(.text+0x41): undefined reference to `g_regex_match'
re.c:(.text+0x54): undefined reference to `g_match_info_fetch'
re.c:(.text+0x6e): undefined reference to `g_print'
re.c:(.text+0x7a): undefined reference to `g_free'
re.c:(.text+0x8b): undefined reference to `g_match_info_next'
re.c:(.text+0x97): undefined reference to `g_match_info_matches'
re.c:(.text+0xa7): undefined reference to `g_match_info_free'
re.c:(.text+0xb3): undefined reference to `g_regex_unref'
collect2: ld returned 1 exit status
make: *** [re] Error 1

# Need to installed libglib2.0-dev some system specific install that will
# provide a value for pkg-config
INCLUDES=$(shell pkg-config --libs --cflags glib-2.0)
CC=gcc $(INCLUDES)
PROJECT=re

# Targets
full: clean compile

clean:
    rm $(PROJECT)

compile:
    $(CC) $(PROJECT).c -o $(PROJECT)

$> glib-config
No command 'glib-config' found, did you mean:
 Command 'gdlib-config' from package 'libgd2-xpm-dev' (main)
 Command 'gdlib-config' from package 'libgd2-noxpm-dev' (main)
glib-config: command not found

re.c:(.text+0xd6): undefined reference to `print_uppercase_words'

void print_upppercase_words(const gchar *string)

gcc -o re re.o -lglib-2.0

re.o: re.c
        $(CC) -I<includes> -o $@ -c $^

re: re.o
        $(CC) $^ -l<libraries> -o $@

CFLAGS=$(shell pkg-config --cflags glib-2.0)
LDLIBS=$(shell pkg-config --libs glib-2.0)
CC=gcc

re: re.o