$ git clone -n https://src.fedoraproject.org/forks/hypersa/rpms/ghc-haskell-src-exts-util.git /var/lib/mock/f39-build-2227883-53056/root/chroot_tmpdir/scmroot/ghc-haskell-src-exts-util
Cloning into '/var/lib/mock/f39-build-2227883-53056/root/chroot_tmpdir/scmroot/ghc-haskell-src-exts-util'...
$ git fetch origin f571ef65a04d93045955a2435927f2a7ae1f0998:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/forks/hypersa/rpms/ghc-haskell-src-exts-util
 * [new ref]         f571ef65a04d93045955a2435927f2a7ae1f0998 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f571ef6 rv64 rebuild