$ git clone -n https://src.fedoraproject.org/rpms/rust-alloc-no-stdlib.git /var/lib/mock/f45-build-40034-767/root/chroot_tmpdir/scmroot/rust-alloc-no-stdlib
Cloning into '/var/lib/mock/f45-build-40034-767/root/chroot_tmpdir/scmroot/rust-alloc-no-stdlib'...
$ git fetch origin 9bdfdc4243abe7f8faa050dee8dabe7265d6bc79:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-alloc-no-stdlib
 * [new ref]         9bdfdc4243abe7f8faa050dee8dabe7265d6bc79 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9bdfdc4 Regenerate with rust2rpm v28