cc -pthread -Wall -Wextra -Werror=implicit-function-declaration threads/thrd_join.c -o threads/thrd_join -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -liconv threads/thrd_join.c:3:10: fatal error: 'threads.h' file not found 3 | #include | ^~~~~~~~~~~ 1 error generated.