$ git clone -n https://src.fedoraproject.org/rpms/ghc-kan-extensions.git /var/lib/mock/f41-build-side-1-2908513-34741/root/chroot_tmpdir/scmroot/ghc-kan-extensions
Cloning into '/var/lib/mock/f41-build-side-1-2908513-34741/root/chroot_tmpdir/scmroot/ghc-kan-extensions'...
$ git fetch origin e4ff407f771be8df95dd5d1ee5662f39f33b547b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-kan-extensions
 * [new ref]         e4ff407f771be8df95dd5d1ee5662f39f33b547b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e4ff407 update to 5.2.6