$ git clone -n https://src.fedoraproject.org/rpms/rust-downcast-rs.git /var/lib/mock/f45-build-41387-782/root/chroot_tmpdir/scmroot/rust-downcast-rs
Cloning into '/var/lib/mock/f45-build-41387-782/root/chroot_tmpdir/scmroot/rust-downcast-rs'...
$ git fetch origin 41b3e9d9a67607e33b1da481a143a6cfbc705908:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-downcast-rs
 * [new ref]         41b3e9d9a67607e33b1da481a143a6cfbc705908 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 41b3e9d Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild