$ git clone -n https://src.fedoraproject.org/rpms/rust-crypto-hash.git /var/lib/mock/f41-build-side-1-2940053-35321/root/chroot_tmpdir/scmroot/rust-crypto-hash
Cloning into '/var/lib/mock/f41-build-side-1-2940053-35321/root/chroot_tmpdir/scmroot/rust-crypto-hash'...
$ git fetch origin 3633206dd69abcdb248a7c3bff2e7c3510da280d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-crypto-hash
 * [new ref]         3633206dd69abcdb248a7c3bff2e7c3510da280d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3633206 unused leaf package for more than two release cycles