$ git clone -n https://src.fedoraproject.org/rpms/R-fastmatch.git /var/lib/mock/f45-build-6064-346/root/chroot_tmpdir/scmroot/R-fastmatch
Cloning into '/var/lib/mock/f45-build-6064-346/root/chroot_tmpdir/scmroot/R-fastmatch'...
$ git fetch origin 82c4b49dd468337114ac87ae61df739f254e4c8c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-fastmatch
 * [new ref]         82c4b49dd468337114ac87ae61df739f254e4c8c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 82c4b49 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild