$ git clone -n https://src.fedoraproject.org/rpms/python-demjson.git /var/lib/mock/f45-build-30336-644/root/chroot_tmpdir/scmroot/python-demjson
Cloning into '/var/lib/mock/f45-build-30336-644/root/chroot_tmpdir/scmroot/python-demjson'...
$ git fetch origin 81ca8c3806f34d886fb7b68775cf68d05dac08c4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-demjson
 * [new ref]         81ca8c3806f34d886fb7b68775cf68d05dac08c4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 81ca8c3 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild