$ git clone -n https://src.fedoraproject.org/rpms/ghc-JuicyPixels.git /var/lib/mock/f45-build-9914-411/root/chroot_tmpdir/scmroot/ghc-JuicyPixels
Cloning into '/var/lib/mock/f45-build-9914-411/root/chroot_tmpdir/scmroot/ghc-JuicyPixels'...
$ git fetch origin 88147191c334090c2ab4ba1c6761cd50894b9b24:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-JuicyPixels
 * [new ref]         88147191c334090c2ab4ba1c6761cd50894b9b24 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8814719 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild