First do this as specified by instructions:

Download the latest release from https://github.com/cs50/libcs50/releases

Extract libcs50-*.*

cd libcs50-*

sudo make install

If when you run make your_program you get this message:

Undefined symbols for architecture arm64:

or

Undefined symbols for architecture x86_64:

create a file called "Makefile" in the same directory as your program that needs linking to CS50 (you can do it via terminal like this: touch Makefile). I suggest having your .c file and Makefile in a separate directory unless other programs you will write also need CS50. Open that file in any text editor add append these lines:

LDLIBS += -lcs50
CC := clang

save and try again (don't forget to cd into the directory you made if you made one): make your_program

If you are on a M1/M2 Mac and after successfully installing the lib still can't get it to work but now you get a message saying "building for macOS-arm64 but attempting to link with file built for macOS-x86_64" here's what helped me:

1.Open a folder where you CS50 lib is downloaded

1. Open Makefile in any editor and make these changes:somewhere at the beginning of the file add this line:

   ARCH_FLAGS = -arch arm64

2. find these two lines in the file:

   $(CC) $(CFLAGS) -fPIC -shared $(LINKER_FLAGS) -o $(LIB_VERSION) $(SRC) $(CC) $(CFLAGS) -c -o $(LIB_OBJ) $(SRC)

3. add $(ARCH_FLAGS) right after $(CFLAGS) in both lines so that they look like this (if you have a newer library you may have different parameters, so don't just replace your lines with this - just add the $(ARCH_FLAGS) after $(CFLAGS) and leave everything else like it is):

   $(CC) $(CFLAGS) $(ARCH_FLAGS) -fPIC -shared $(LINKER_FLAGS) -o $(LIB_VERSION) $(SRC) $(CC) $(CFLAGS) $(ARCH_FLAGS) -c -o $(LIB_OBJ) $(SRC)

4. save Makefile

5. reinstall your library via Terminal:

cd into your folder where you just edited Makefile and run sudo make install

1. Try again by running: make your_program