cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration wctype/iswalpha_l.c -o wctype/iswalpha_l -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm -lpthread  -liconv
wctype/iswalpha_l.c:15:8: error: call to undeclared function 'iswalpha_l'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
   15 |         if ( !iswalpha_l(wc1, locale) )
      |               ^
wctype/iswalpha_l.c:15:8: note: did you mean 'iswalpha'?
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/___wctype.h:90:1: note: 'iswalpha' declared here
   90 | iswalpha(wint_t _wc)
      | ^
1 error generated.