$ git clone -n https://src.fedoraproject.org/rpms/erlang-base64url.git /var/lib/mock/f45-build-8224-379/root/chroot_tmpdir/scmroot/erlang-base64url
Cloning into '/var/lib/mock/f45-build-8224-379/root/chroot_tmpdir/scmroot/erlang-base64url'...
$ git fetch origin 7773f761972315ddef440fe298602bc22a42b80c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/erlang-base64url
 * [new ref]         7773f761972315ddef440fe298602bc22a42b80c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7773f76 Switch to declarative build (f45+)