$ git clone -n https://src.fedoraproject.org/rpms/rust-downcast.git /var/lib/mock/f40-build-2036036-48007/root/chroot_tmpdir/scmroot/rust-downcast
Cloning into '/var/lib/mock/f40-build-2036036-48007/root/chroot_tmpdir/scmroot/rust-downcast'...
$ git fetch origin 9f89c0cfe4ed3c757302ef560be586384d9c4f0c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-downcast
 * [new ref]         9f89c0cfe4ed3c757302ef560be586384d9c4f0c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9f89c0c Regenerate with rust2rpm v24