$ git clone -n https://src.fedoraproject.org/rpms/ghc-nanospec.git /var/lib/mock/f45-build-10556-418/root/chroot_tmpdir/scmroot/ghc-nanospec
Cloning into '/var/lib/mock/f45-build-10556-418/root/chroot_tmpdir/scmroot/ghc-nanospec'...
$ git fetch origin 853b2da12edfd443dd0f5a37da92f59bfef57801:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-nanospec
 * [new ref]         853b2da12edfd443dd0f5a37da92f59bfef57801 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 853b2da Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild