compilation errors under macOS (BigSur in this case)

[chriskuku]

$ gcc --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/4.2.1
Apple clang version 13.0.0 (clang-1300.0.29.3)
Target: x86_64-apple-darwin20.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
$

Excerpt from output of make:

.h" -o "out/include/drat/argp.gch"
include/drat/argp.h:6:10: error: 'argp.h' file not found with <angled> include; use "quotes" instead
#include <argp.h>
         ^~~~~~~~
         "argp.h"
include/drat/argp.h:30:53: error: array has incomplete element type 'const struct argp_option'
extern const struct argp_option argp_options_globals[];
                                                    ^
include/drat/argp.h:30:21: note: forward declaration of 'struct argp_option'
extern const struct argp_option argp_options_globals[];
                    ^
include/drat/argp.h:31:1: error: unknown type name 'error_t'
error_t argp_parser_command(int key, char* arg, struct argp_state* state);
^
include/drat/argp.h:31:56: error: declaration of 'struct argp_state' will not be visible outside of this function [-Werror,-Wvisibility]
error_t argp_parser_command(int key, char* arg, struct argp_state* state);
                                                       ^
include/drat/argp.h:32:1: error: unknown type name 'error_t'
error_t argp_parser_globals(int key, char* arg, struct argp_state* state);
^
include/drat/argp.h:32:56: error: declaration of 'struct argp_state' will not be visible outside of this function [-Werror,-Wvisibility]
error_t argp_parser_globals(int key, char* arg, struct argp_state* state);
                                                       ^
include/drat/argp.h:35:45: error: array has incomplete element type 'const struct argp_child'
extern const struct argp_child argp_children[];
                                            ^
include/drat/argp.h:35:21: note: forward declaration of 'struct argp_child'
extern const struct argp_child argp_children[];
                    ^
7 errors generated.
make: *** [out/include/drat/argp.gch] Error 1

Sorry, I overlooked that argp_standalone is required (a home_brew port). Will try that and ignore my post.

[chriskuku]

"drat" compiled fine now.