$ git clone -n https://src.fedoraproject.org/rpms/ghc-memory.git /var/lib/mock/f38-build-side-42-init-devel-912964-28703/root/chroot_tmpdir/scmroot/ghc-memory
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-912964-28703/root/chroot_tmpdir/scmroot/ghc-memory'...
$ git fetch origin dfb0543efef811aa8bd9db9c2c2f13b7f9fb8afe:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-memory
 * [new ref]         dfb0543efef811aa8bd9db9c2c2f13b7f9fb8afe -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dfb0543 patch for 32bit Word64 primitives