$ git clone -n https://src.fedoraproject.org/rpms/ghc-explicit-exception.git /var/lib/mock/f41-build-838074-159539/root/chroot_tmpdir/scmroot/ghc-explicit-exception
Cloning into '/var/lib/mock/f41-build-838074-159539/root/chroot_tmpdir/scmroot/ghc-explicit-exception'...
$ git fetch origin 448b9b201fec055f5e3101eba56fe4fdbddd66cf:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-explicit-exception
 * [new ref]         448b9b201fec055f5e3101eba56fe4fdbddd66cf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 448b9b2 refresh .cabal revision