$ git clone -n https://src.fedoraproject.org/rpms/rust-thiserror-impl.git /var/lib/mock/f41-build-side-1-3134319-39731/root/chroot_tmpdir/scmroot/rust-thiserror-impl
Cloning into '/var/lib/mock/f41-build-side-1-3134319-39731/root/chroot_tmpdir/scmroot/rust-thiserror-impl'...
$ git fetch origin 1f797a8a30364329c0c2bf9a35c71a69046a5576:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-thiserror-impl
 * [new ref]         1f797a8a30364329c0c2bf9a35c71a69046a5576 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1f797a8 Update to version 1.0.69