$ git clone -n https://src.fedoraproject.org/rpms/jboss-jaxrs-2.0-api.git /var/lib/mock/f38-build-side-42-init-devel-677010-26691/root/chroot_tmpdir/scmroot/jboss-jaxrs-2.0-api
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-677010-26691/root/chroot_tmpdir/scmroot/jboss-jaxrs-2.0-api'...
$ git fetch origin 15800989bd13cda8a42b896f2721b34145990b22:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jboss-jaxrs-2.0-api
 * [new ref]         15800989bd13cda8a42b896f2721b34145990b22 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1580098 Remove dependency on jaxb-api2 compat package