```c ../src/canbd.c: In function 'ca_block_device_establish_friendly_name': ../src/canbd.c:179:13: error: implicit declaration of function 'writev'; did you mean 'write'? [-Werror=implicit-function-declaration] n = writev(d->friendly_name_fd, (struct iovec[]) { ^~~~~~ write ../src/canbd.c:179:13: warning: nested extern declaration of 'writev' [-Wnested-externs] ```