$ git clone -n https://src.fedoraproject.org/rpms/rust-subprocess.git /var/lib/mock/f41-build-side-1-3134929-39764/root/chroot_tmpdir/scmroot/rust-subprocess
Cloning into '/var/lib/mock/f41-build-side-1-3134929-39764/root/chroot_tmpdir/scmroot/rust-subprocess'...
$ git fetch origin 6ccce86215cb5c61296ecf1dfecbf27e5f6ca727:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-subprocess
 * [new ref]         6ccce86215cb5c61296ecf1dfecbf27e5f6ca727 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6ccce86 unused leaf package for more than two release cycles