$ git clone -n https://src.fedoraproject.org/rpms/xreader.git /var/lib/mock/f40-build-1937303-25150/root/chroot_tmpdir/scmroot/xreader
Cloning into '/var/lib/mock/f40-build-1937303-25150/root/chroot_tmpdir/scmroot/xreader'...
$ git fetch origin 1051eff91659696c7d5a53167d326dcbf7bc2f93:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xreader
 * [new ref]         1051eff91659696c7d5a53167d326dcbf7bc2f93 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1051eff Update to 4.2.1