There looks to be one or two issues close together.
aarch64-linux-gnu-gcc -pthread build/temp.linux-aarch64-2.7/scratch/tmp/timer_createC7TyLh.o -o build/temp.linux-aarch64-2.7/scratch/a.out
build/temp.linux-aarch64-2.7/scratch/tmp/timer_createC7TyLh.o: In function `main':
/tmp/timer_createC7TyLh.c:2: undefined reference to `timer_create'
collect2: error: ld returned 1 exit status
aarch64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fno-strict-aliasing -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC -Izmq/utils -Izmq/backend/cython -Izmq/devices -c build/temp.linux-aarch64-2.7/scratch/vers.c -o build/temp.linux-aarch64-2.7/scratch/vers.o
build/temp.linux-aarch64-2.7/scratch/vers.c:4:17: fatal error: zmq.h: No such file or directory
compilation terminated.
From: http://build.ros.org/view/Kbin_uxv8_uXv8/job/Kbin_uxv8_uXv8__pyros_interfaces_ros__ubuntu_xenial_arm64__binary/13/console
There looks to be one or two issues close together.