$ git clone -n https://src.fedoraproject.org/rpms/rubygem-em-socksify.git /var/lib/mock/f45-build-34924-692/root/chroot_tmpdir/scmroot/rubygem-em-socksify
Cloning into '/var/lib/mock/f45-build-34924-692/root/chroot_tmpdir/scmroot/rubygem-em-socksify'...
$ git fetch origin 7e8da36e2131739c151920c407e7afbc3e9f141a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-em-socksify
 * [new ref]         7e8da36e2131739c151920c407e7afbc3e9f141a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7e8da36 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild