/opt/IBM/openxlC/17.1.1/bin/ibm-clang -pthread  -Wall -Wextra -Werror=implicit-function-declaration stdlib/ptsname_r.c -o stdlib/ptsname_r -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -latomic
stdlib/ptsname_r.c:24:15: error: call to undeclared function 'ptsname_r'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]
        int errnum = ptsname_r(controller, name, sizeof(name));
                     ^
1 error generated.