Failing to link libusb to C project on Mac - c

Question

I've got libusb installed on Mac OS X using Homebrew, and is located at
/usr/local/Cellar/libusb
it's tree looks as follows :
.
└── 1.0.9
├── AUTHORS
├── COPYING
├── ChangeLog
├── INSTALL_RECEIPT.json
├── NEWS
├── README
├── TODO
├── include
│   └── libusb-1.0
│   └── libusb.h
└── lib
├── libusb-1.0.0.dylib
├── libusb-1.0.a
├── libusb-1.0.dylib -> libusb-1.0.0.dylib
└── pkgconfig
└── libusb-1.0.pc
I have the following code:
#include <stdio.h>
#include <stdlib.h>
#include <libusb.h>
int main(void) {
puts("USB Test v0.0.1");
//libusb_device **devices;
libusb_context *ctx = NULL;
int result;
result = libusb_init(&ctx);
if (result < 0) {
puts("USB initialization error!");
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
...but compilation yields the following:
22:08:26 **** Incremental Build of configuration debug for project usb_test ****
make all
Building target: usb_test
Invoking: MacOS X C Linker
gcc -L/usr/local/Cellar/libusb/1.0.9/lib -o "usb_test" ./src/usb_test.o -l/usr/local/Cellar/libusb/1.0.9/lib/libusb-1.0.a
ld: library not found for -l/usr/local/Cellar/libusb/1.0.9/lib/libusb-1.0.a
collect2: ld returned 1 exit status
make: *** [usb_test] Error 1
22:08:26 Build Finished (took 68ms)
Why isn't it finding the libusb library?

Answer 1

Somewhere you have a wrong linker flag.
-l/usr/local/Cellar/libusb/1.0.9/lib/libusb-1.0.a
Should just be:
/usr/local/Cellar/libusb/1.0.9/lib/libusb-1.0.a
In this case you do not need to specify the linker search path, so
-L/usr/local/Cellar/libusb/1.0.9/lib is not needed.
If you don't want to link statically to that libusb-1.0.a, but link to the .dylib, you need to keep -L/usr/local/Cellar/libusb/1.0.9/lib and replace
-l/usr/local/Cellar/libusb/1.0.9/lib/libusb-1.0.a
with
-lusb-1.0