$ git clone -n https://src.fedoraproject.org/rpms/perl-Crypt-U2F-Server.git /var/lib/mock/f41-build-side-1-2931583-35142/root/chroot_tmpdir/scmroot/perl-Crypt-U2F-Server
Cloning into '/var/lib/mock/f41-build-side-1-2931583-35142/root/chroot_tmpdir/scmroot/perl-Crypt-U2F-Server'...
$ git fetch origin 18697f15bc622331f61cb739cf9c61f4a138044f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Crypt-U2F-Server
 * [new ref]         18697f15bc622331f61cb739cf9c61f4a138044f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 18697f1 Update to 0.47 (RHBZ#2261447, RHBZ#2280641, RHBZ#2292219, RHBZ#2302694)