$ git clone -n https://src.fedoraproject.org/rpms/rust-vm-allocator.git /var/lib/mock/f45-build-46099-830/root/chroot_tmpdir/scmroot/rust-vm-allocator
Cloning into '/var/lib/mock/f45-build-46099-830/root/chroot_tmpdir/scmroot/rust-vm-allocator'...
$ git fetch origin 6c87d6f97271602b8ad73d2874d9e15d3e07f723:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-vm-allocator
 * [new ref]         6c87d6f97271602b8ad73d2874d9e15d3e07f723 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6c87d6f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild