$ git clone -n https://src.fedoraproject.org/rpms/ghc-aeson.git /var/lib/mock/f38-build-side-42-init-devel-831424-28369/root/chroot_tmpdir/scmroot/ghc-aeson
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-831424-28369/root/chroot_tmpdir/scmroot/ghc-aeson'...
$ git fetch origin cfbc4c27f99efabb7690dfed82286b725ec6f1de:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-aeson
 * [new ref]         cfbc4c27f99efabb7690dfed82286b725ec6f1de -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cfbc4c2 update to 2.0.3.0