merge #559 into opencontainers/umoci:main #1592

Job	Run time
macos	27s
linux-ci-image	1m 15s
release	16s
validate	31s
unit	1m 8s
integration (opensuse/leap:latest)	11m 23s
integration (centos:latest)	19m 13s
integration (debian:latest)	12m 33s
integration (ubuntu:latest)	9m 31s
integration (fedora:latest)	14m 18s
coverage	16s
	1h 10m 51s

Provide feedback