CPIO is used at run time in 25 crates (of which 5 optionally). It is a direct run-time dependency in 16 crates. It's used only as a dev dependency in 1 crate.

Depender (with downloads and own rev deps) CPIO version
5.8K 7 rpm ^0.2
220 3 rpm-rs ^0.2
rpm-infra ^0.2
coreos-installer >=0.2.1, <0.3
1 flop ^0.2.2
1 fez ^0.2
wyrcan ^0.2.0
linux-package-analyzer ^0.2.2
kanga-rpm-rs ^0.2
rpm-rs-temporary ^0.2
cpiotools ^0.2.1
nix-cpio-generator ^0.2.2
debuginfod-rs ^0.2.2
filesystem_in_a_file optional ^0.2
hyper-static-server optional ^0.2.1
moth optional ^0.2.2