cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration strings/strcasecmp_l.c -o strings/strcasecmp_l -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm -lpthread  -liconv
strings/strcasecmp_l.c:13:7: error: call to undeclared function 'strcasecmp_l'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
   13 |         if ( strcasecmp_l("foo", "FOO", locale) != 0 )
      |              ^
strings/strcasecmp_l.c:13:7: note: did you mean 'strcasecmp'?
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/_strings.h:81:6: note: 'strcasecmp' declared here
   81 | int      strcasecmp(const char *, const char *);
      |          ^
1 error generated.