conflicts: 1 shift/reduce, 3 reduce/reduce
/bin/sh: pkg-config: command not found
/bin/sh: pkg-config: command not found
/bin/sh: pkg-config: command not found
/bin/sh: pkg-config: command not found
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Undefined symbols for architecture x86_64:
  "_png_create_info_struct", referenced from:
      _initialize_png in makepng.o
      _output_png_file in makepng.o
  "_png_create_read_struct", referenced from:
      _initialize_png in makepng.o
  "_png_create_write_struct", referenced from:
      _output_png_file in makepng.o
  "_png_data_freer", referenced from:
      _rgba_PLTE_palette in makepng.o
  "_png_destroy_read_struct", referenced from:
      _input_png_file in makepng.o
  "_png_destroy_write_struct", referenced from:
      _output_png_file in makepng.o
  "_png_free_data", referenced from:
      _get_text in makepng.o
  "_png_get_PLTE", referenced from:
      _indexed_png_to_raw in makepng.o
      _rgba_PLTE_palette in makepng.o
  "_png_get_bit_depth", referenced from:
      _initialize_png in makepng.o
  "_png_get_color_type", referenced from:
      _initialize_png in makepng.o
  "_png_get_image_height", referenced from:
      _initialize_png in makepng.o
  "_png_get_image_width", referenced from:
      _initialize_png in makepng.o
  "_png_get_rowbytes", referenced from:
      _read_png in makepng.o
  "_png_get_tRNS", referenced from:
      _indexed_png_to_raw in makepng.o
  "_png_get_text", referenced from:
      _get_text in makepng.o
  "_png_get_valid", referenced from:
      _truecolor_png_to_raw in makepng.o
      _rgba_png_palette in makepng.o
  "_png_init_io", referenced from:
      _initialize_png in makepng.o
      _output_png_file in makepng.o
  "_png_read_end", referenced from:
      _read_png in makepng.o
  "_png_read_image", referenced from:
      _read_png in makepng.o
  "_png_read_info", referenced from:
      _initialize_png in makepng.o
  "_png_read_update_info", referenced from:
      _read_png in makepng.o
  "_png_set_IHDR", referenced from:
      _output_png_file in makepng.o
  "_png_set_PLTE", referenced from:
      _output_png_file in makepng.o
  "_png_set_add_alpha", referenced from:
      _truecolor_png_to_raw in makepng.o
  "_png_set_expand_gray_1_2_4_to_8", referenced from:
      _grayscale_png_to_raw in makepng.o
  "_png_set_gray_to_rgb", referenced from:
      _grayscale_png_to_raw in makepng.o
  "_png_set_longjmp_fn", referenced from:
      _initialize_png in makepng.o
      _output_png_file in makepng.o
  "_png_set_packing", referenced from:
      _indexed_png_to_raw in makepng.o
  "_png_set_scale_16", referenced from:
      _truecolor_png_to_raw in makepng.o
  "_png_set_tRNS_to_alpha", referenced from:
      _truecolor_png_to_raw in makepng.o
  "_png_set_text", referenced from:
      _get_text in makepng.o
      _set_text in makepng.o
  "_png_write_end", referenced from:
      _output_png_file in makepng.o
  "_png_write_image", referenced from:
      _output_png_file in makepng.o
  "_png_write_info", referenced from:
      _output_png_file in makepng.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [rgbgfx] Error 1