gcc -pthread  -Wall -Wextra -Werror=implicit-function-declaration signal/psiginfo.c -o signal/psiginfo -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lxnet -lsocket -latomic
signal/psiginfo.c: In function 'main':
signal/psiginfo.c:20:9: error: implicit declaration of function 'psiginfo' [-Wimplicit-function-declaration]
   20 |         psiginfo(&info, "foo");
      |         ^~~~~~~~