$ git clone -n https://src.fedoraproject.org/rpms/rust-libz-rs-sys.git /var/lib/mock/f45-build-35457-695/root/chroot_tmpdir/scmroot/rust-libz-rs-sys
Cloning into '/var/lib/mock/f45-build-35457-695/root/chroot_tmpdir/scmroot/rust-libz-rs-sys'...
$ git fetch origin c59010fb61d0ae9d2edca42867f578eb6d6ac5b5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-libz-rs-sys
 * [new ref]         c59010fb61d0ae9d2edca42867f578eb6d6ac5b5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c59010f Update to version 0.6.7; Fixes RHBZ#2510679