The 3 warnings reported are:
os.c:872:7: warning: Although the value stored to 'ptr' is used in the enclosing expression, the value is never actually read from 'ptr'
if ((ptr = strtok_r(command, " \t", &last)) == NULL) {
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
--
rpz.c:1117:10: warning: Although the value stored to 'zbits' is used in the enclosing expression, the value is never actually read from 'zbits'
return (zbits &= x);
^ ~
1 warning generated.
--
openssleddsa_link.c:532:10: warning: Although the value stored to 'err' is used in the enclosing expression, the value is never actually read from 'err'
while ((err = ERR_get_error()) != 0) {
^ ~~~~~~~~~~~~~~~
1 warning generated.