$ git clone -n https://src.fedoraproject.org/rpms/rust-zlib-rs.git /var/lib/mock/f45-build-46345-833/root/chroot_tmpdir/scmroot/rust-zlib-rs
Cloning into '/var/lib/mock/f45-build-46345-833/root/chroot_tmpdir/scmroot/rust-zlib-rs'...
$ git fetch origin 9fd6c63a99fabc76a96b0ae457720d4d92faa57a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-zlib-rs
 * [new ref]         9fd6c63a99fabc76a96b0ae457720d4d92faa57a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9fd6c63 Update to version 0.6.7; Fixes RHBZ#2510638