$ git clone -n https://src.fedoraproject.org/rpms/jaxb-istack-commons.git /var/lib/mock/f41-build-1283318-23209/root/chroot_tmpdir/scmroot/jaxb-istack-commons
Cloning into '/var/lib/mock/f41-build-1283318-23209/root/chroot_tmpdir/scmroot/jaxb-istack-commons'...
$ git fetch origin a66e037b3fd74365543c16e496d90ee62398d27f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jaxb-istack-commons
 * [new ref]         a66e037b3fd74365543c16e496d90ee62398d27f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a66e037 Rebuilt for java-21-openjdk as system jdk