Makefile compiling and linking problems - c

Question

So I've been trying to search for a solution that Im having with my make file currently. I get the error:
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/9/../../../x86_64-linux-gnu/Scrt1.o: in function `_start':
(.text+0x24): undefined reference to `main'
So I have 5 files in my src folder: find.c, rebalance.c, remove.c, lib.c, and insert.c. In my src/bin folder I just have main.c and in another folder 'include' outside of src I have bst.h. This is what my makefile looks like:
all: static bin shared
mkdir -p build/bin
mkdir -p build/lib
mkdir -p build/objects
mv *.o build/objects
mv *.a build/lib
mv main build/bin
mv libbst.so build/lib
static:
gcc src/lib.c -c -I include
gcc src/find.c -c -I include
gcc src/insert.c -c -I include
gcc src/rebalance.c -c -I include
gcc src/remove.c -c -I include
ar rcs libbst.a find.o insert.o lib.o rebalance.o remove.o
shared:
gcc -c -o lib.o src/lib.c
gcc -c -o find.o src/find.c
gcc -c -o insert.o src/insert.c
gcc -c -o rebalance.o src/rebalance.c
gcc -c -o remove.o src/remove.c
gcc -shared -o libbst.so find.o insert.o lib.o rebalance.o remove.o
bin:
gcc src/lib.c -c -I include
gcc lib.o -o lib -lbst -L.
gcc src/bin/main.c -c -I include
gcc main.o -o main -lbst -L.
clean:
rm -rf *.so *.a *.o main build
install:
Im assuming that I'm just not using the right commands to link everything together. This always fails in the 'bin' section of the Makefile. I would really appreciate any help or advice on what I can do here, im kind of stumped right now.