$ git clone -n https://src.fedoraproject.org/rpms/rust-cfg_aliases.git /var/lib/mock/f45-build-40742-775/root/chroot_tmpdir/scmroot/rust-cfg_aliases
Cloning into '/var/lib/mock/f45-build-40742-775/root/chroot_tmpdir/scmroot/rust-cfg_aliases'...
$ git fetch origin 9b7a975e2a6d1b8f3a31145b71e7fc9f9b1b7e67:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-cfg_aliases
 * [new ref]         9b7a975e2a6d1b8f3a31145b71e7fc9f9b1b7e67 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9b7a975 Update to version 0.2.2; Fixes RHBZ#2501412