$ git clone -n https://src.fedoraproject.org/rpms/ghc-temporary.git /var/lib/mock/f39-build-1922847-42989/root/chroot_tmpdir/scmroot/ghc-temporary
Cloning into '/var/lib/mock/f39-build-1922847-42989/root/chroot_tmpdir/scmroot/ghc-temporary'...
$ git fetch origin f6706ebe4a37e7c3296fef661a083bd7bf439e3a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-temporary
 * [new ref]         f6706ebe4a37e7c3296fef661a083bd7bf439e3a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f6706eb bump release