$ git clone -n https://src.fedoraproject.org/rpms/rubygem-semantic.git /var/lib/mock/f45-build-35285-694/root/chroot_tmpdir/scmroot/rubygem-semantic
Cloning into '/var/lib/mock/f45-build-35285-694/root/chroot_tmpdir/scmroot/rubygem-semantic'...
$ git fetch origin e2b4dacdf6c7a35bb48a00f6dec087169cadb5de:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-semantic
 * [new ref]         e2b4dacdf6c7a35bb48a00f6dec087169cadb5de -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e2b4dac Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild