$ git clone -n https://src.fedoraproject.org/rpms/jakarta-mail.git /var/lib/mock/f41-build-1627251-24124/root/chroot_tmpdir/scmroot/jakarta-mail
Cloning into '/var/lib/mock/f41-build-1627251-24124/root/chroot_tmpdir/scmroot/jakarta-mail'...
$ git fetch origin ab04cff277de232df877d551c08d3cb0b169a56f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jakarta-mail
 * [new ref]         ab04cff277de232df877d551c08d3cb0b169a56f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ab04cff Update to upstream version 2.1.3