little program to use if you're canoscan lide30 scanner says "device not configured"

canoscan_build.sh

#!/usr/bin/env bash

export C_INCLUDE_PATH=/usr/local/include/libusb-1.0
export LIBRARY_PATH=/usr/local/lib
(O=canoscan ; cc canoscan_unit.c -o "${O}" -lusb-1.0 && printf "PROGRAM\t%s\n" "${O}")

canoscan_unit.c

// I used this little program when my canoscan lide30 scanner would say "device not configured"
// when using sane-backends on Macos.
//
// The symptom (device not configured) would show up when running `sane-find-scanner -v -v` (you need
// the two -v flag to show the verbose diagnostic.
//

// To compile and use, install libusb (which should already have been installed if like me you
// installed the sane-backends using brew) and compile via canoscan_build.sh

#include <libusb.h>

#include <stdio.h>
#include <stdlib.h>

#define UU_LIBUSB_GUARD(x) for (int err = x; err != 0; exit(1)) {	\
    printf("unexpected libusb error: %s\n", libusb_strerror(err));	\
  }

libusb_device_handle* uu_find_canoscan_device(libusb_context* ctx)
{
  return libusb_open_device_with_vid_pid(ctx, 0x04a9, 0x220e);
}

int main(int argc, char** argv)
{
  printf("Remember you can set the LIBUSB_DEBUG environment variable to turn debugging on.\n");
  int rc = 0;
  libusb_context* ctx;
  UU_LIBUSB_GUARD(libusb_init(&ctx));
  libusb_device_handle* canoscan = uu_find_canoscan_device(ctx);
  if (!canoscan) {
    printf("Could not find canoscan lide30 device\n");
    rc = 1;
    goto done;
  }
  printf("Opened Canoscan LiDE 30 device\n");
  UU_LIBUSB_GUARD(libusb_set_configuration(canoscan, 1)); // This is forcefully activating the configuration
 done_with_device:
  libusb_close(canoscan);
 done:
  libusb_exit(ctx);
  return rc;
}