unziptar: better debugging when extraction fails #201

Job	Run time
fresh-macos-test	3m 38s
homebrew-macos-test-and-lint	10m 15s
homebrew-macos-test	4m 29s
distro-test (ubuntu:latest)	1m 56s
distro-test (fedora:latest)	2m 53s
distro-test (debian:latest)	1m 36s
distro-test (alpine:latest)	1m 26s
distro-test (manjarolinux/base)	1m 56s
distro-test (opensuse/leap)	5m 23s
distro-test (opensuse/tumbleweed)	1m 56s
distro-test (kalilinux/kali-rolling)	2m 6s
distro-test (voidlinux/voidlinux)	1m 56s
	39m 30s

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