$ git clone -n https://src.fedoraproject.org/rpms/rust-spin0.5.git /var/lib/mock/f39-build-1517201-35697/root/chroot_tmpdir/scmroot/rust-spin0.5
Cloning into '/var/lib/mock/f39-build-1517201-35697/root/chroot_tmpdir/scmroot/rust-spin0.5'...
$ git fetch origin 9f9225488d18f4c8e96d30452995364b4fc45274:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-spin0.5
 * [new ref]         9f9225488d18f4c8e96d30452995364b4fc45274 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9f92254 Regenerate with rust2rpm v24